81936408 has 16 divisors (see below), whose sum is σ = 204841080. Its totient is φ = 27312128.

The previous prime is 81936403. The next prime is 81936431. The reversal of 81936408 is 80463918.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81936401) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1706985 + ... + 1707032.

Almost surely, 2^81936408 is an apocalyptic number.

It is an amenable number.

81936408 is an abundant number, since it is smaller than the sum of its proper divisors (122904672).

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

81936408 is a wasteful number, since it uses less digits than its factorization.

81936408 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3414026 (or 3414022 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 39.

The square root of 81936408 is about 9051.8731763100. The cubic root of 81936408 is about 434.3358129202.

The spelling of 81936408 in words is "eighty-one million, nine hundred thirty-six thousand, four hundred eight".