81563064 has 32 divisors (see below), whose sum is σ = 222445440. Its totient is φ = 24716000.

The previous prime is 81563023. The next prime is 81563101. The reversal of 81563064 is 46036518.

It is a hoax number, since the sum of its digits (33) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (33).

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, 154212 + ... + 154739.

It is an arithmetic number, because the mean of its divisors is an integer number (6951420).

Almost surely, 2^81563064 is an apocalyptic number.

It is an amenable number.

81563064 is an abundant number, since it is smaller than the sum of its proper divisors (140882376).

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

81563064 is a wasteful number, since it uses less digits than its factorization.

81563064 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 308971 (or 308967 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 33.

The square root of 81563064 is about 9031.2271591407. The cubic root of 81563064 is about 433.6751233744.

The spelling of 81563064 in words is "eighty-one million, five hundred sixty-three thousand, sixty-four".