81515384 has 16 divisors (see below), whose sum is σ = 154995120. Its totient is φ = 40183360.

The previous prime is 81515353. The next prime is 81515429. The reversal of 81515384 is 48351518.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 71189 + ... + 72324.

It is an arithmetic number, because the mean of its divisors is an integer number (9687195).

Almost surely, 2^81515384 is an apocalyptic number.

It is an amenable number.

81515384 is a deficient number, since it is larger than the sum of its proper divisors (73479736).

81515384 is a wasteful number, since it uses less digits than its factorization.

81515384 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 143590 (or 143586 counting only the distinct ones).

The product of its digits is 19200, while the sum is 35.

The square root of 81515384 is about 9028.5870433861. The cubic root of 81515384 is about 433.5906012087.

The spelling of 81515384 in words is "eighty-one million, five hundred fifteen thousand, three hundred eighty-four".