81512368 has 40 divisors (see below), whose sum is σ = 188345088. Its totient is φ = 33413952.

The previous prime is 81512363. The next prime is 81512371. The reversal of 81512368 is 86321518.

It is a super-2 number, since 2×81512368² = 13288532273934848, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (81512363) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13246 + ... + 18397.

Almost surely, 2^81512368 is an apocalyptic number.

It is an amenable number.

81512368 is an abundant number, since it is smaller than the sum of its proper divisors (106832720).

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

81512368 is a wasteful number, since it uses less digits than its factorization.

81512368 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31681 (or 31675 counting only the distinct ones).

The product of its digits is 11520, while the sum is 34.

The square root of 81512368 is about 9028.4200168136. The cubic root of 81512368 is about 433.5852536481.

The spelling of 81512368 in words is "eighty-one million, five hundred twelve thousand, three hundred sixty-eight".