81539312 has 10 divisors (see below), whose sum is σ = 157982448. Its totient is φ = 40769648.

The previous prime is 81539299. The next prime is 81539351. The reversal of 81539312 is 21393518.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2548088 + ... + 2548119.

Almost surely, 2^81539312 is an apocalyptic number.

It is an amenable number.

81539312 is a deficient number, since it is larger than the sum of its proper divisors (76443136).

81539312 is a wasteful number, since it uses less digits than its factorization.

81539312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5096215 (or 5096209 counting only the distinct ones).

The product of its digits is 6480, while the sum is 32.

The square root of 81539312 is about 9029.9120704468. The cubic root of 81539312 is about 433.6330224075.

The spelling of 81539312 in words is "eighty-one million, five hundred thirty-nine thousand, three hundred twelve".