81513284 has 6 divisors (see below), whose sum is σ = 142648254. Its totient is φ = 40756640.

The previous prime is 81513259. The next prime is 81513319. The reversal of 81513284 is 48231518.

It can be written as a sum of positive squares in only one way, i.e., 67240000 + 14273284 = 8200^2 + 3778^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 81513284.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10189157 + ... + 10189164.

It is an arithmetic number, because the mean of its divisors is an integer number (23774709).

Almost surely, 2^81513284 is an apocalyptic number.

It is an amenable number.

81513284 is a deficient number, since it is larger than the sum of its proper divisors (61134970).

81513284 is a wasteful number, since it uses less digits than its factorization.

81513284 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20378325 (or 20378323 counting only the distinct ones).

The product of its digits is 7680, while the sum is 32.

The square root of 81513284 is about 9028.4707453699. The cubic root of 81513284 is about 433.5868777885.

The spelling of 81513284 in words is "eighty-one million, five hundred thirteen thousand, two hundred eighty-four".