81564078 has 32 divisors (see below), whose sum is σ = 167443200. Its totient is φ = 26477696.

The previous prime is 81564061. The next prime is 81564097. The reversal of 81564078 is 87046518.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 38983 + ... + 41021.

It is an arithmetic number, because the mean of its divisors is an integer number (5232600).

Almost surely, 2^81564078 is an apocalyptic number.

81564078 is an abundant number, since it is smaller than the sum of its proper divisors (85879122).

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

81564078 is a wasteful number, since it uses less digits than its factorization.

81564078 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2216.

The product of its (nonzero) digits is 53760, while the sum is 39.

The square root of 81564078 is about 9031.2832975165. The cubic root of 81564078 is about 433.6769205308.

The spelling of 81564078 in words is "eighty-one million, five hundred sixty-four thousand, seventy-eight".