398858840 has 64 divisors (see below), whose sum is σ = 914004000. Its totient is φ = 156625920.

The previous prime is 398858833. The next prime is 398858851. The reversal of 398858840 is 48858893.

It is a super-2 number, since 2×398858840² = 318176748492291200, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 644051 + ... + 644669.

Almost surely, 2^398858840 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 398858840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (457002000).

398858840 is an abundant number, since it is smaller than the sum of its proper divisors (515145160).

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

398858840 is a wasteful number, since it uses less digits than its factorization.

398858840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 900 (or 896 counting only the distinct ones).

The product of its (nonzero) digits is 2211840, while the sum is 53.

The square root of 398858840 is about 19971.4506233273. The cubic root of 398858840 is about 736.1049541175.

Adding to 398858840 its sum of digits (53), we get a palindrome (398858893).

The spelling of 398858840 in words is "three hundred ninety-eight million, eight hundred fifty-eight thousand, eight hundred forty".