81867406 has 32 divisors (see below), whose sum is σ = 131544000. Its totient is φ = 38142720.

The previous prime is 81867391. The next prime is 81867413. The reversal of 81867406 is 60476818.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 411295 + ... + 411493.

It is an arithmetic number, because the mean of its divisors is an integer number (4110750).

Almost surely, 2^81867406 is an apocalyptic number.

81867406 is a deficient number, since it is larger than the sum of its proper divisors (49676594).

81867406 is a wasteful number, since it uses less digits than its factorization.

81867406 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 444.

The product of its (nonzero) digits is 64512, while the sum is 40.

The square root of 81867406 is about 9048.0608972310. The cubic root of 81867406 is about 434.2138546950.

The spelling of 81867406 in words is "eighty-one million, eight hundred sixty-seven thousand, four hundred six".