398438688400 has 135 divisors (see below), whose sum is σ = 984974490801. Its totient is φ = 154886238720.

The previous prime is 398438688371. The next prime is 398438688433. The reversal of 398438688400 is 4886834893.

The square root of 398438688400 is 631220.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 13 ways, for example, as 287480413584 + 110958274816 = 536172^2 + 333104^2 .

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 467102374 + ... + 467103226.

Almost surely, 2^398438688400 is an apocalyptic number.

398438688400 is the 631220-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 398438688400

398438688400 is an abundant number, since it is smaller than the sum of its proper divisors (586535802401).

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

398438688400 is an frugal number, since it uses more digits than its factorization.

398438688400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1798 (or 897 counting only the distinct ones).

The product of its (nonzero) digits is 31850496, while the sum is 61.

The spelling of 398438688400 in words is "three hundred ninety-eight billion, four hundred thirty-eight million, six hundred eighty-eight thousand, four hundred".