398865664 has 36 divisors (see below), whose sum is σ = 798468160. Its totient is φ = 198858240.

The previous prime is 398865653. The next prime is 398865683. The reversal of 398865664 is 466568893.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 94969 + ... + 99079.

Almost surely, 2^398865664 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 398865664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (399234080).

398865664 is an abundant number, since it is smaller than the sum of its proper divisors (399602496).

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

398865664 is an equidigital number, since it uses as much as digits as its factorization.

398865664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4506 (or 4492 counting only the distinct ones).

The product of its digits is 7464960, while the sum is 55.

The square root of 398865664 is about 19971.6214664709. The cubic root of 398865664 is about 736.1091520534.

The spelling of 398865664 in words is "three hundred ninety-eight million, eight hundred sixty-five thousand, six hundred sixty-four".