401555421 has 8 divisors (see below), whose sum is σ = 594896960. Its totient is φ = 267703596.

The previous prime is 401555417. The next prime is 401555467. The reversal of 401555421 is 124555104.

It is not a de Polignac number, because 401555421 - 2² = 401555417 is a prime.

It is a super-2 number, since 2×401555421² = 322493512268974482, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 14872423 = 401555421 / (4 + 0 + 1 + 5 + 5 + 5 + 4 + 2 + 1).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (401555471) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 7436185 + ... + 7436238.

It is an arithmetic number, because the mean of its divisors is an integer number (74362120).

Almost surely, 2^401555421 is an apocalyptic number.

It is an amenable number.

401555421 is a deficient number, since it is larger than the sum of its proper divisors (193341539).

401555421 is a wasteful number, since it uses less digits than its factorization.

401555421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14872432 (or 14872426 counting only the distinct ones).

The product of its (nonzero) digits is 4000, while the sum is 27.

The square root of 401555421 is about 20038.8477962182. The cubic root of 401555421 is about 737.7601011516.

The spelling of 401555421 in words is "four hundred one million, five hundred fifty-five thousand, four hundred twenty-one".