401865880 has 64 divisors (see below), whose sum is σ = 1000117440. Its totient is φ = 144364032.

The previous prime is 401865869. The next prime is 401865889. The reversal of 401865880 is 88568104.

It is a super-2 number, since 2×401865880² = 322992371016348800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (401865889) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 8797 + ... + 29683.

It is an arithmetic number, because the mean of its divisors is an integer number (15626835).

Almost surely, 2^401865880 is an apocalyptic number.

401865880 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 401865880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (500058720).

401865880 is an abundant number, since it is smaller than the sum of its proper divisors (598251560).

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

401865880 is a wasteful number, since it uses less digits than its factorization.

401865880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20948 (or 20944 counting only the distinct ones).

The product of its (nonzero) digits is 61440, while the sum is 40.

The square root of 401865880 is about 20046.5927279426. The cubic root of 401865880 is about 737.9501830588.

The spelling of 401865880 in words is "four hundred one million, eight hundred sixty-five thousand, eight hundred eighty".