81923544 has 48 divisors (see below), whose sum is σ = 234931320. Its totient is φ = 25701120.

The previous prime is 81923537. The next prime is 81923551. The reversal of 81923544 is 44532918.

It is an interprime number because it is at equal distance from previous prime (81923537) and next prime (81923551).

It is a super-2 number, since 2×81923544² = 13422934123039872, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 81923499 and 81923508.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 32242 + ... + 34689.

Almost surely, 2^81923544 is an apocalyptic number.

It is an amenable number.

81923544 is an abundant number, since it is smaller than the sum of its proper divisors (153007776).

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

81923544 is a wasteful number, since it uses less digits than its factorization.

81923544 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66960 (or 66953 counting only the distinct ones).

The product of its digits is 34560, while the sum is 36.

The square root of 81923544 is about 9051.1625772604. The cubic root of 81923544 is about 434.3130815180.

The spelling of 81923544 in words is "eighty-one million, nine hundred twenty-three thousand, five hundred forty-four".