81351608 has 32 divisors (see below), whose sum is σ = 167378400. Its totient is φ = 36835968.

The previous prime is 81351581. The next prime is 81351629. The reversal of 81351608 is 80615318.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1868 + ... + 12891.

It is an arithmetic number, because the mean of its divisors is an integer number (5230575).

Almost surely, 2^81351608 is an apocalyptic number.

It is an amenable number.

81351608 is an abundant number, since it is smaller than the sum of its proper divisors (86026792).

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

81351608 is a wasteful number, since it uses less digits than its factorization.

81351608 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14831 (or 14827 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 32.

The square root of 81351608 is about 9019.5126254139. The cubic root of 81351608 is about 433.3000247902.

The spelling of 81351608 in words is "eighty-one million, three hundred fifty-one thousand, six hundred eight".