66817404 has 18 divisors (see below), whose sum is σ = 168899640. Its totient is φ = 22272456.

The previous prime is 66817393. The next prime is 66817447. The reversal of 66817404 is 40471866.

It is a tau number, because it is divible by the number of its divisors (18).

It is a Harshad number since it is a multiple of its sum of digits (36), and also a Moran number because the ratio is a prime number: 1856039 = 66817404 / (6 + 6 + 8 + 1 + 7 + 4 + 0 + 4).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 927984 + ... + 928055.

Almost surely, 2^66817404 is an apocalyptic number.

It is an amenable number.

66817404 is an abundant number, since it is smaller than the sum of its proper divisors (102082236).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66817404 is a wasteful number, since it uses less digits than its factorization.

66817404 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1856049 (or 1856044 counting only the distinct ones).

The product of its (nonzero) digits is 32256, while the sum is 36.

The square root of 66817404 is about 8174.1913361506. The cubic root of 66817404 is about 405.7855079666.

The spelling of 66817404 in words is "sixty-six million, eight hundred seventeen thousand, four hundred four".