400081920 has 264 divisors, whose sum is σ = 1486809792. Its totient is φ = 89948160.

The previous prime is 400081919. The next prime is 400081949. The reversal of 400081920 is 29180004.

It is a hoax number, since the sum of its digits (24) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6558690 + ... + 6558750.

Almost surely, 2^400081920 is an apocalyptic number.

400081920 is a gapful number since it is divisible by the number (40) 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 400081920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (743404896).

400081920 is an abundant number, since it is smaller than the sum of its proper divisors (1086727872).

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

400081920 is an equidigital number, since it uses as much as digits as its factorization.

400081920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 157 (or 78 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 24.

The square root of 400081920 is about 20002.0478951531. The cubic root of 400081920 is about 736.8565956048.

The spelling of 400081920 in words is "four hundred million, eighty-one thousand, nine hundred twenty".