81571412 has 24 divisors (see below), whose sum is σ = 154173600. Its totient is φ = 37539936.

The previous prime is 81571331. The next prime is 81571433. The reversal of 81571412 is 21417518.

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, 17639 + ... + 21777.

It is an arithmetic number, because the mean of its divisors is an integer number (6423900).

Almost surely, 2^81571412 is an apocalyptic number.

It is an amenable number.

81571412 is a deficient number, since it is larger than the sum of its proper divisors (72602188).

81571412 is a wasteful number, since it uses less digits than its factorization.

81571412 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4535 (or 4533 counting only the distinct ones).

The product of its digits is 2240, while the sum is 29.

The square root of 81571412 is about 9031.6893214946. The cubic root of 81571412 is about 433.6899184554.

It can be divided in two parts, 815 and 71412, that added together give a palindrome (72227).

The spelling of 81571412 in words is "eighty-one million, five hundred seventy-one thousand, four hundred twelve".