81923562 has 112 divisors (see below), whose sum is σ = 220348800. Its totient is φ = 22324896.

The previous prime is 81923551. The next prime is 81923591. The reversal of 81923562 is 26532918.

81923562 is a `hidden beast` number, since 8 + 1 + 92 + 3 + 562 = 666.

It is a super-2 number, since 2×81923562² = 13422940021535688, which contains 22 as substring.

It is an unprimeable number.

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 55 ways as a sum of consecutive naturals, for example, 234564 + ... + 234912.

It is an arithmetic number, because the mean of its divisors is an integer number (1967400).

Almost surely, 2^81923562 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81923562, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (110174400).

81923562 is an abundant number, since it is smaller than the sum of its proper divisors (138425238).

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

81923562 is a wasteful number, since it uses less digits than its factorization.

81923562 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 399 (or 384 counting only the distinct ones).

The product of its digits is 25920, while the sum is 36.

The square root of 81923562 is about 9051.1635716078. The cubic root of 81923562 is about 434.3131133267.

The spelling of 81923562 in words is "eighty-one million, nine hundred twenty-three thousand, five hundred sixty-two".