66390645 has 16 divisors (see below), whose sum is σ = 106785792. Its totient is φ = 35221440.

The previous prime is 66390629. The next prime is 66390679. The reversal of 66390645 is 54609366.

It is a happy number.

It is not a de Polignac number, because 66390645 - 2⁴ = 66390629 is a prime.

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, 8722 + ... + 14451.

It is an arithmetic number, because the mean of its divisors is an integer number (6674112).

Almost surely, 2^66390645 is an apocalyptic number.

It is an amenable number.

66390645 is a deficient number, since it is larger than the sum of its proper divisors (40395147).

66390645 is a wasteful number, since it uses less digits than its factorization.

66390645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23372.

The product of its (nonzero) digits is 116640, while the sum is 39.

The square root of 66390645 is about 8148.0454711544. The cubic root of 66390645 is about 404.9197524286.

The spelling of 66390645 in words is "sixty-six million, three hundred ninety thousand, six hundred forty-five".