81864213700 has 18 divisors (see below), whose sum is σ = 177645343946. Its totient is φ = 32745685440.

The previous prime is 81864213667. The next prime is 81864213719. The reversal of 81864213700 is 731246818.

It can be written as a sum of positive squares in 3 ways, for example, as 4137156 + 81860076544 = 2034^2 + 286112^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 409320969 + ... + 409321168.

Almost surely, 2^81864213700 is an apocalyptic number.

It is an amenable number.

81864213700 is an abundant number, since it is smaller than the sum of its proper divisors (95781130246).

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

81864213700 is a wasteful number, since it uses less digits than its factorization.

81864213700 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 818642151 (or 818642144 counting only the distinct ones).

The product of its (nonzero) digits is 64512, while the sum is 40.

The spelling of 81864213700 in words is "eighty-one billion, eight hundred sixty-four million, two hundred thirteen thousand, seven hundred".