66904431 has 16 divisors (see below), whose sum is σ = 99580800. Its totient is φ = 39604320.

The previous prime is 66904393. The next prime is 66904457. The reversal of 66904431 is 13440966.

It is not a de Polignac number, because 66904431 - 2⁷ = 66904303 is a prime.

It is a super-2 number, since 2×66904431² = 8952405774867522, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a junction number, because it is equal to n+sod(n) for n = 66904392 and 66904401.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66904471) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 22156 + ... + 24993.

It is an arithmetic number, because the mean of its divisors is an integer number (6223800).

Almost surely, 2^66904431 is an apocalyptic number.

66904431 is a deficient number, since it is larger than the sum of its proper divisors (32676369).

66904431 is a wasteful number, since it uses less digits than its factorization.

66904431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47206.

The product of its (nonzero) digits is 15552, while the sum is 33.

The square root of 66904431 is about 8179.5128828067. The cubic root of 66904431 is about 405.9616046747.

The spelling of 66904431 in words is "sixty-six million, nine hundred four thousand, four hundred thirty-one".