64406660 has 24 divisors (see below), whose sum is σ = 137808216. Its totient is φ = 25276160.

The previous prime is 64406633. The next prime is 64406669. The reversal of 64406660 is 6660446.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 25867396 + 38539264 = 5086^2 + 6208^2 .

It is not an unprimeable number, because it can be changed into a prime (64406669) 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, 29321 + ... + 31440.

It is an arithmetic number, because the mean of its divisors is an integer number (5742009).

Almost surely, 2^64406660 is an apocalyptic number.

It is an amenable number.

64406660 is an abundant number, since it is smaller than the sum of its proper divisors (73401556).

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

64406660 is a wasteful number, since it uses less digits than its factorization.

64406660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60823 (or 60821 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 32.

The square root of 64406660 is about 8025.3760036524. The cubic root of 64406660 is about 400.8454202360.

The spelling of 64406660 in words is "sixty-four million, four hundred six thousand, six hundred sixty".