64644660 has 36 divisors (see below), whose sum is σ = 196089348. Its totient is φ = 17238528.

The previous prime is 64644649. The next prime is 64644677. The reversal of 64644660 is 6644646.

It is a happy number.

64644660 is a `hidden beast` number, since 6 + 4 + 644 + 6 + 6 + 0 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 29289744 + 35354916 = 5412^2 + 5946^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 179389 + ... + 179748.

Almost surely, 2^64644660 is an apocalyptic number.

64644660 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

64644660 is an abundant number, since it is smaller than the sum of its proper divisors (131444688).

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

64644660 is a wasteful number, since it uses less digits than its factorization.

64644660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 359152 (or 359147 counting only the distinct ones).

The product of its (nonzero) digits is 82944, while the sum is 36.

The square root of 64644660 is about 8040.1902962554. The cubic root of 64644660 is about 401.3385573308.

The spelling of 64644660 in words is "sixty-four million, six hundred forty-four thousand, six hundred sixty".