81263831 has 16 divisors (see below), whose sum is σ = 91300608. Its totient is φ = 71702400.

The previous prime is 81263797. The next prime is 81263857. The reversal of 81263831 is 13836218.

It is a happy number.

It is not a de Polignac number, because 81263831 - 2¹⁰ = 81262807 is a prime.

It is a super-2 number, since 2×81263831² = 13207620457593122, 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 (81263881) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 51551 + ... + 53103.

It is an arithmetic number, because the mean of its divisors is an integer number (5706288).

Almost surely, 2^81263831 is an apocalyptic number.

81263831 is a deficient number, since it is larger than the sum of its proper divisors (10036777).

81263831 is a wasteful number, since it uses less digits than its factorization.

81263831 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1702.

The product of its digits is 6912, while the sum is 32.

The square root of 81263831 is about 9014.6453618542. The cubic root of 81263831 is about 433.1441275900.

The spelling of 81263831 in words is "eighty-one million, two hundred sixty-three thousand, eight hundred thirty-one".