81870568 has 16 divisors (see below), whose sum is σ = 165315780. Its totient is φ = 37786368.

The previous prime is 81870559. The next prime is 81870571. The reversal of 81870568 is 86507818.

It can be written as a sum of positive squares in 2 ways, for example, as 79174404 + 2696164 = 8898^2 + 1642^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 393505 + ... + 393712.

Almost surely, 2^81870568 is an apocalyptic number.

It is an amenable number.

81870568 is an abundant number, since it is smaller than the sum of its proper divisors (83445212).

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

81870568 is a wasteful number, since it uses less digits than its factorization.

81870568 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 787236 (or 787232 counting only the distinct ones).

The product of its (nonzero) digits is 107520, while the sum is 43.

The square root of 81870568 is about 9048.2356291158. The cubic root of 81870568 is about 434.2194448991.

The spelling of 81870568 in words is "eighty-one million, eight hundred seventy thousand, five hundred sixty-eight".