401999624 has 48 divisors (see below), whose sum is σ = 844416900. Its totient is φ = 179122944.

The previous prime is 401999623. The next prime is 401999641. The reversal of 401999624 is 426999104.

It can be written as a sum of positive squares in 6 ways, for example, as 14303524 + 387696100 = 3782^2 + 19690^2 .

It is a super-2 number, since 2×401999624² = 323207395392282752, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (401999623) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 34082 + ... + 44334.

Almost surely, 2^401999624 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 401999624, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (422208450).

401999624 is an abundant number, since it is smaller than the sum of its proper divisors (442417276).

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

401999624 is a wasteful number, since it uses less digits than its factorization.

401999624 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10314 (or 10297 counting only the distinct ones).

The product of its (nonzero) digits is 139968, while the sum is 44.

The square root of 401999624 is about 20049.9282791735. The cubic root of 401999624 is about 738.0320391101.

The spelling of 401999624 in words is "four hundred one million, nine hundred ninety-nine thousand, six hundred twenty-four".