398531820 has 48 divisors (see below), whose sum is σ = 1131187680. Its totient is φ = 104818176.

The previous prime is 398531813. The next prime is 398531831. The reversal of 398531820 is 28135893.

It is a super-2 number, since 2×398531820² = 317655223105024800, which contains 22 as substring.

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, 41115 + ... + 49874.

It is an arithmetic number, because the mean of its divisors is an integer number (23566410).

Almost surely, 2^398531820 is an apocalyptic number.

398531820 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

398531820 is an abundant number, since it is smaller than the sum of its proper divisors (732655860).

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

398531820 is a wasteful number, since it uses less digits than its factorization.

398531820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 91074 (or 91072 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 39.

The square root of 398531820 is about 19963.2617575385. The cubic root of 398531820 is about 735.9037243121.

The spelling of 398531820 in words is "three hundred ninety-eight million, five hundred thirty-one thousand, eight hundred twenty".