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31809900 = 22352106033
BaseRepresentation
bin111100101011…
…0000101101100
32012212002222110
41321112011230
531120404100
63053444020
7534244143
oct171260554
965762873
1031809900
1116a57281
12a7a0610
136789a35
14432075a
152bd5250
hex1e5616c

31809900 has 36 divisors (see below), whose sum is σ = 92037512. Its totient is φ = 8482560.

The previous prime is 31809887. The next prime is 31809901. The reversal of 31809900 is 990813.

It is a happy number.

It is a Smith number, since the sum of its digits (30) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31809901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 52717 + ... + 53316.

Almost surely, 231809900 is an apocalyptic number.

31809900 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

31809900 is an abundant number, since it is smaller than the sum of its proper divisors (60227612).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

31809900 is a wasteful number, since it uses less digits than its factorization.

31809900 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 106050 (or 106043 counting only the distinct ones).

The product of its (nonzero) digits is 1944, while the sum is 30.

The square root of 31809900 is about 5640.0265956820. The cubic root of 31809900 is about 316.8502843990.

The spelling of 31809900 in words is "thirty-one million, eight hundred nine thousand, nine hundred".

Divisors: 1 2 3 4 5 6 10 12 15 20 25 30 50 60 75 100 150 300 106033 212066 318099 424132 530165 636198 1060330 1272396 1590495 2120660 2650825 3180990 5301650 6361980 7952475 10603300 15904950 31809900