81470656 has 28 divisors (see below), whose sum is σ = 163192968. Its totient is φ = 40351232.

The previous prime is 81470639. The next prime is 81470659. The reversal of 81470656 is 65607418.

It is not an unprimeable number, because it can be changed into a prime (81470659) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 900 + ... + 12796.

Almost surely, 2^81470656 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81470656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (81596484).

81470656 is an abundant number, since it is smaller than the sum of its proper divisors (81722312).

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

81470656 is a wasteful number, since it uses less digits than its factorization.

81470656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12016 (or 12006 counting only the distinct ones).

The product of its (nonzero) digits is 40320, while the sum is 37.

The square root of 81470656 is about 9026.1096824712. The cubic root of 81470656 is about 433.5112820763.

The spelling of 81470656 in words is "eighty-one million, four hundred seventy thousand, six hundred fifty-six".