66904 has 8 divisors (see below), whose sum is σ = 125460. Its totient is φ = 33448.

The previous prime is 66889. The next prime is 66919. The reversal of 66904 is 40966.

66904 = 57² + 58² + ... + 72².

It is an interprime number because it is at equal distance from previous prime (66889) and next prime (66919).

It is a tau number, because it is divible by the number of its divisors (8).

It is a super-2 number, since 2×66904² = 8952290432, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

66904 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4174 + ... + 4189.

2⁶⁶⁹⁰⁴ is an apocalyptic number.

It is an amenable number.

66904 is a deficient number, since it is larger than the sum of its proper divisors (58556).

66904 is a wasteful number, since it uses less digits than its factorization.

66904 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8369 (or 8365 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 25.

The square root of 66904 is about 258.6580754587. The cubic root of 66904 is about 40.5960732935.

The spelling of 66904 in words is "sixty-six thousand, nine hundred four".