401556 has 24 divisors (see below), whose sum is σ = 948640. Its totient is φ = 132192.

The previous prime is 401551. The next prime is 401567. The reversal of 401556 is 655104.

401556 = T₁₃₁ + T₁₃₂ + ... + T₁₆₆.

It is a happy number.

It is a super-2 number, since 2×401556² = 322494442272, which contains 22 as substring.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 401556.

It is not an unprimeable number, because it can be changed into a prime (401551) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1155 + ... + 1461.

2⁴⁰¹⁵⁵⁶ is an apocalyptic number.

It is an amenable number.

401556 is an abundant number, since it is smaller than the sum of its proper divisors (547084).

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

401556 is a wasteful number, since it uses less digits than its factorization.

401556 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 423 (or 421 counting only the distinct ones).

The product of its (nonzero) digits is 600, while the sum is 21.

The square root of 401556 is about 633.6844640671. The cubic root of 401556 is about 73.7760455742.

It can be divided in two parts, 40 and 1556, that added together give a triangular number (1596 = T₅₆).

The spelling of 401556 in words is "four hundred one thousand, five hundred fifty-six".