421638664 has 16 divisors (see below), whose sum is σ = 793969020. Its totient is φ = 209913600.

The previous prime is 421638661. The next prime is 421638703. The reversal of 421638664 is 466836124.

It can be written as a sum of positive squares in 2 ways, for example, as 407636100 + 14002564 = 20190^2 + 3742^2 .

It is not an unprimeable number, because it can be changed into a prime (421638661) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 111237 + ... + 114964.

Almost surely, 2^421638664 is an apocalyptic number.

It is an amenable number.

421638664 is a deficient number, since it is larger than the sum of its proper divisors (372330356).

421638664 is a wasteful number, since it uses less digits than its factorization.

421638664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 226440 (or 226436 counting only the distinct ones).

The product of its digits is 165888, while the sum is 40.

The square root of 421638664 is about 20533.8419201084. The cubic root of 421638664 is about 749.8599228765.

The spelling of 421638664 in words is "four hundred twenty-one million, six hundred thirty-eight thousand, six hundred sixty-four".