401656559 has 2 divisors, whose sum is σ = 401656560. Its totient is φ = 401656558.

The previous prime is 401656547. The next prime is 401656573. The reversal of 401656559 is 955656104.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 401656559 - 2¹² = 401652463 is a prime.

It is a super-2 number, since 2×401656559² = 322655982775440962, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (401656529) 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, 200828279 + 200828280.

It is an arithmetic number, because the mean of its divisors is an integer number (200828280).

Almost surely, 2^401656559 is an apocalyptic number.

401656559 is a deficient number, since it is larger than the sum of its proper divisors (1).

401656559 is an equidigital number, since it uses as much as digits as its factorization.

401656559 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 162000, while the sum is 41.

The square root of 401656559 is about 20041.3711856250. The cubic root of 401656559 is about 737.8220347509.

It can be divided in two parts, 4016565 and 59, that multiplied together give a triangular number (236977335 = T₂₁₇₇₀).

The spelling of 401656559 in words is "four hundred one million, six hundred fifty-six thousand, five hundred fifty-nine".