81471570 has 32 divisors (see below), whose sum is σ = 196311168. Its totient is φ = 21639168.

The previous prime is 81471557. The next prime is 81471581. The reversal of 81471570 is 7517418.

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, 2427 + ... + 12993.

It is an arithmetic number, because the mean of its divisors is an integer number (6134724).

Almost surely, 2^81471570 is an apocalyptic number.

81471570 is an abundant number, since it is smaller than the sum of its proper divisors (114839598).

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

81471570 is a wasteful number, since it uses less digits than its factorization.

81471570 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10834.

The product of its (nonzero) digits is 7840, while the sum is 33.

The square root of 81471570 is about 9026.1603132229. The cubic root of 81471570 is about 433.5129032237.

Adding to 81471570 its reverse (7517418), we get a palindrome (88988988).

The spelling of 81471570 in words is "eighty-one million, four hundred seventy-one thousand, five hundred seventy".