64637666 has 16 divisors (see below), whose sum is σ = 100884480. Its totient is φ = 31026240.

The previous prime is 64637663. The next prime is 64637669. The reversal of 64637666 is 66673646.

It is an interprime number because it is at equal distance from previous prime (64637663) and next prime (64637669).

It is not an unprimeable number, because it can be changed into a prime (64637663) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3770 + ... + 11978.

It is an arithmetic number, because the mean of its divisors is an integer number (6305280).

Almost surely, 2^64637666 is an apocalyptic number.

64637666 is a deficient number, since it is larger than the sum of its proper divisors (36246814).

64637666 is a wasteful number, since it uses less digits than its factorization.

64637666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8369.

The product of its digits is 653184, while the sum is 44.

The square root of 64637666 is about 8039.7553445363. The cubic root of 64637666 is about 401.3240830076.

The spelling of 64637666 in words is "sixty-four million, six hundred thirty-seven thousand, six hundred sixty-six".