81922384872 has 48 divisors (see below), whose sum is σ = 234924489540. Its totient is φ = 25701139968.

The previous prime is 81922384861. The next prime is 81922384877. The reversal of 81922384872 is 27848322918.

81922384872 is a `hidden beast` number, since 8 + 192 + 2 + 384 + 8 + 72 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 79961135076 + 1961249796 = 282774^2 + 44286^2 .

It is a super-2 number, since 2×81922384872² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (81922384877) 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, 33463803 + ... + 33466250.

Almost surely, 2^81922384872 is an apocalyptic number.

It is an amenable number.

81922384872 is an abundant number, since it is smaller than the sum of its proper divisors (153002104668).

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

81922384872 is a wasteful number, since it uses less digits than its factorization.

81922384872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66930082 (or 66930075 counting only the distinct ones).

The product of its digits is 3096576, while the sum is 54.

The spelling of 81922384872 in words is "eighty-one billion, nine hundred twenty-two million, three hundred eighty-four thousand, eight hundred seventy-two".