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31689269 = 41772909
BaseRepresentation
bin111100011100…
…0101000110101
32012121222111122
41320320220311
531103024034
63051113325
7533232353
oct170705065
965558448
1031689269
1116984687
12a742845
136746b61
1442cc7d3
152bae62e
hex1e38a35

31689269 has 4 divisors (see below), whose sum is σ = 32462220. Its totient is φ = 30916320.

The previous prime is 31689263. The next prime is 31689277. The reversal of 31689269 is 96298613.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 96298613 = 718713399.

It can be written as a sum of positive squares in 2 ways, for example, as 17724100 + 13965169 = 4210^2 + 3737^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2k-31689269 is a prime.

It is a super-2 number, since 2×316892692 = 2008419539508722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31689263) 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 3 ways as a sum of consecutive naturals, for example, 386414 + ... + 386495.

It is an arithmetic number, because the mean of its divisors is an integer number (8115555).

Almost surely, 231689269 is an apocalyptic number.

It is an amenable number.

31689269 is a deficient number, since it is larger than the sum of its proper divisors (772951).

31689269 is an equidigital number, since it uses as much as digits as its factorization.

31689269 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 772950.

The product of its digits is 139968, while the sum is 44.

The square root of 31689269 is about 5629.3222505023. The cubic root of 31689269 is about 316.4492521793.

The spelling of 31689269 in words is "thirty-one million, six hundred eighty-nine thousand, two hundred sixty-nine".

Divisors: 1 41 772909 31689269