64646640400 has 30 divisors (see below), whose sum is σ = 155313554522. Its totient is φ = 25858656000.

The previous prime is 64646640353. The next prime is 64646640439. The reversal of 64646640400 is 404664646.

It is a happy number.

64646640400 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 3 ways, for example, as 1440657936 + 63205982464 = 37956^2 + 251408^2 .

It is a Harshad number since it is a multiple of its sum of digits (40).

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, 80807901 + ... + 80808700.

Almost surely, 2^64646640400 is an apocalyptic number.

It is an amenable number.

64646640400 is an abundant number, since it is smaller than the sum of its proper divisors (90666914122).

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

64646640400 is a wasteful number, since it uses less digits than its factorization.

64646640400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 161616619 (or 161616608 counting only the distinct ones).

The product of its (nonzero) digits is 331776, while the sum is 40.

The spelling of 64646640400 in words is "sixty-four billion, six hundred forty-six million, six hundred forty thousand, four hundred".