398021520 has 320 divisors, whose sum is σ = 1417409280. Its totient is φ = 91693056.

The previous prime is 398021497. The next prime is 398021537. The reversal of 398021520 is 25120893.

It is a happy number.

It is a super-2 number, since 2×398021520² = 316842260766220800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 4795399 + ... + 4795481.

It is an arithmetic number, because the mean of its divisors is an integer number (4429404).

Almost surely, 2^398021520 is an apocalyptic number.

398021520 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 398021520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (708704640).

398021520 is an abundant number, since it is smaller than the sum of its proper divisors (1019387760).

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

398021520 is a wasteful number, since it uses less digits than its factorization.

398021520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 194 (or 188 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 30.

The square root of 398021520 is about 19950.4766860343. The cubic root of 398021520 is about 735.5894942231.

The spelling of 398021520 in words is "three hundred ninety-eight million, twenty-one thousand, five hundred twenty".