81206464 has 28 divisors (see below), whose sum is σ = 161848800. Its totient is φ = 40425728.

The previous prime is 81206429. The next prime is 81206483. The reversal of 81206464 is 46460218.

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, 12642 + ... + 17950.

Almost surely, 2^81206464 is an apocalyptic number.

It is an amenable number.

81206464 is a deficient number, since it is larger than the sum of its proper divisors (80642336).

81206464 is a wasteful number, since it uses less digits than its factorization.

81206464 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5560 (or 5550 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 31.

The square root of 81206464 is about 9011.4629223007. The cubic root of 81206464 is about 433.0421796991.

The spelling of 81206464 in words is "eighty-one million, two hundred six thousand, four hundred sixty-four".