400751988 has 144 divisors (see below), whose sum is σ = 1185125760. Its totient is φ = 104461056.

The previous prime is 400751951. The next prime is 400751993. The reversal of 400751988 is 889157004.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent 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 47 ways as a sum of consecutive naturals, for example, 787078 + ... + 787586.

It is an arithmetic number, because the mean of its divisors is an integer number (8230040).

Almost surely, 2^400751988 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 400751988, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (592562880).

400751988 is an abundant number, since it is smaller than the sum of its proper divisors (784373772).

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

400751988 is a wasteful number, since it uses less digits than its factorization.

400751988 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 646 (or 637 counting only the distinct ones).

The product of its (nonzero) digits is 80640, while the sum is 42.

The square root of 400751988 is about 20018.7908725777. The cubic root of 400751988 is about 737.2677352669.

The spelling of 400751988 in words is "four hundred million, seven hundred fifty-one thousand, nine hundred eighty-eight".