400990581 has 12 divisors (see below), whose sum is σ = 600661152. Its totient is φ = 267326892.

The previous prime is 400990561. The next prime is 400990589. The reversal of 400990581 is 185099004.

It is not a de Polignac number, because 400990581 - 2⁶ = 400990517 is a prime.

It is a super-2 number, since 2×400990581² = 321586892101435122, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (400990589) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 824841 + ... + 825326.

It is an arithmetic number, because the mean of its divisors is an integer number (50055096).

Almost surely, 2^400990581 is an apocalyptic number.

It is an amenable number.

400990581 is a deficient number, since it is larger than the sum of its proper divisors (199670571).

400990581 is an equidigital number, since it uses as much as digits as its factorization.

400990581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1650182 (or 1650170 counting only the distinct ones).

The product of its (nonzero) digits is 12960, while the sum is 36.

The square root of 400990581 is about 20024.7492119127. The cubic root of 400990581 is about 737.4140202744.

The spelling of 400990581 in words is "four hundred million, nine hundred ninety thousand, five hundred eighty-one".