401865620 has 48 divisors (see below), whose sum is σ = 910833168. Its totient is φ = 148055040.

The previous prime is 401865577. The next prime is 401865631. The reversal of 401865620 is 26568104.

It can be written as a sum of positive squares in 8 ways, for example, as 20757136 + 381108484 = 4556^2 + 19522^2 .

It is a super-2 number, since 2×401865620² = 322991953075968800, which contains 22 as substring.

It is a congruent number.

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, 139232 + ... + 142088.

It is an arithmetic number, because the mean of its divisors is an integer number (18975691).

Almost surely, 2^401865620 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 401865620, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (455416584).

401865620 is an abundant number, since it is smaller than the sum of its proper divisors (508967548).

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

401865620 is a wasteful number, since it uses less digits than its factorization.

401865620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3420 (or 3418 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 32.

The square root of 401865620 is about 20046.5862430490. The cubic root of 401865620 is about 737.9500239119.

The spelling of 401865620 in words is "four hundred one million, eight hundred sixty-five thousand, six hundred twenty".