401560021 has 2 divisors, whose sum is σ = 401560022. Its totient is φ = 401560020.

The previous prime is 401559997. The next prime is 401560039. The reversal of 401560021 is 120065104.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 384708996 + 16851025 = 19614^2 + 4105^2 .

It is a cyclic number.

It is not a de Polignac number, because 401560021 - 2⁵ = 401559989 is a prime.

It is a super-2 number, since 2×401560021² = 322500900931040882, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (401560051) 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 as a sum of consecutive naturals, namely, 200780010 + 200780011.

It is an arithmetic number, because the mean of its divisors is an integer number (200780011).

Almost surely, 2^401560021 is an apocalyptic number.

It is an amenable number.

401560021 is a deficient number, since it is larger than the sum of its proper divisors (1).

401560021 is an equidigital number, since it uses as much as digits as its factorization.

401560021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 240, while the sum is 19.

The square root of 401560021 is about 20038.9625729477. The cubic root of 401560021 is about 737.7629182667.

The spelling of 401560021 in words is "four hundred one million, five hundred sixty thousand, twenty-one".