401556304020 has 144 divisors (see below), whose sum is σ = 1246317948288. Its totient is φ = 96400803840.

The previous prime is 401556304007. The next prime is 401556304063. The reversal of 401556304020 is 20403655104.

It is a super-2 number, since 2×401556304020² (a number of 24 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 104611 + ... + 902250.

It is an arithmetic number, because the mean of its divisors is an integer number (8654985752).

Almost surely, 2^401556304020 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 401556304020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (623158974144).

401556304020 is an abundant number, since it is smaller than the sum of its proper divisors (844761644268).

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

401556304020 is a wasteful number, since it uses less digits than its factorization.

401556304020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1006930 (or 1006911 counting only the distinct ones).

The product of its (nonzero) digits is 14400, while the sum is 30.

Adding to 401556304020 its reverse (20403655104), we get a palindrome (421959959124).

The spelling of 401556304020 in words is "four hundred one billion, five hundred fifty-six million, three hundred four thousand, twenty".