81653031 has 12 divisors (see below), whose sum is σ = 118696552. Its totient is φ = 54087696.

The previous prime is 81653027. The next prime is 81653041. The reversal of 81653031 is 13035618.

81653031 is a `hidden beast` number, since 8 + 1 + 653 + 0 + 3 + 1 = 666.

It is not a de Polignac number, because 81653031 - 2² = 81653027 is a prime.

It is a super-2 number, since 2×81653031² = 13334434942973922, 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 = 81652986 and 81653004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81653041) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 27481 + ... + 30306.

Almost surely, 2^81653031 is an apocalyptic number.

81653031 is a deficient number, since it is larger than the sum of its proper divisors (37043521).

81653031 is a wasteful number, since it uses less digits than its factorization.

81653031 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57950 (or 57947 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 27.

The square root of 81653031 is about 9036.2066709433. The cubic root of 81653031 is about 433.8345178813.

Adding to 81653031 its reverse (13035618), we get a palindrome (94688649).

The spelling of 81653031 in words is "eighty-one million, six hundred fifty-three thousand, thirty-one".