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1990231 = 19312109
BaseRepresentation
bin111100101111001010111
310202010002021
413211321113
51002141411
6110354011
722626265
oct7457127
93663067
101990231
11113a321
127bb907
13548b69
1439b435
15294a71
hex1e5e57

1990231 has 12 divisors (see below), whose sum is σ = 2184600. Its totient is φ = 1807920.

The previous prime is 1990229. The next prime is 1990237. The reversal of 1990231 is 1320991.

It is not a de Polignac number, because 1990231 - 21 = 1990229 is a prime.

It is a super-2 number, since 2×19902312 = 7922038866722, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1990196 and 1990205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1990237) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 18205 + ... + 18313.

It is an arithmetic number, because the mean of its divisors is an integer number (182050).

21990231 is an apocalyptic number.

1990231 is the 815-th hex number.

1990231 is a deficient number, since it is larger than the sum of its proper divisors (194369).

1990231 is a wasteful number, since it uses less digits than its factorization.

1990231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 190 (or 159 counting only the distinct ones).

The product of its (nonzero) digits is 486, while the sum is 25.

The square root of 1990231 is about 1410.7554713699. The cubic root of 1990231 is about 125.7866339387.

The spelling of 1990231 in words is "one million, nine hundred ninety thousand, two hundred thirty-one".

Divisors: 1 19 31 109 589 961 2071 3379 18259 64201 104749 1990231