66378654 has 12 divisors (see below), whose sum is σ = 143820456. Its totient is φ = 22126212.

The previous prime is 66378643. The next prime is 66378661. The reversal of 66378654 is 45687366.

66378654 is a `hidden beast` number, since 6 + 637 + 8 + 6 + 5 + 4 = 666.

It is a super-2 number, since 2×66378654² = 8812251413703432, which contains 22 as substring.

It is a Curzon number.

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, 1843834 + ... + 1843869.

It is an arithmetic number, because the mean of its divisors is an integer number (11985038).

Almost surely, 2^66378654 is an apocalyptic number.

66378654 is an abundant number, since it is smaller than the sum of its proper divisors (77441802).

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

66378654 is a wasteful number, since it uses less digits than its factorization.

66378654 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3687711 (or 3687708 counting only the distinct ones).

The product of its digits is 725760, while the sum is 45.

The square root of 66378654 is about 8147.3096172909. The cubic root of 66378654 is about 404.8953730647.

The spelling of 66378654 in words is "sixty-six million, three hundred seventy-eight thousand, six hundred fifty-four".