400402561 has 16 divisors (see below), whose sum is σ = 473639040. Its totient is φ = 334920960.

The previous prime is 400402553. The next prime is 400402571. The reversal of 400402561 is 165204004.

It is a cyclic number.

It is not a de Polignac number, because 400402561 - 2³ = 400402553 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (400402501) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 29560 + ... + 40921.

It is an arithmetic number, because the mean of its divisors is an integer number (29602440).

Almost surely, 2^400402561 is an apocalyptic number.

It is an amenable number.

400402561 is a deficient number, since it is larger than the sum of its proper divisors (73236479).

400402561 is a wasteful number, since it uses less digits than its factorization.

400402561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70536.

The product of its (nonzero) digits is 960, while the sum is 22.

The square root of 400402561 is about 20010.0614941584. The cubic root of 400402561 is about 737.0533914227.

Adding to 400402561 its reverse (165204004), we get a palindrome (565606565).

The spelling of 400402561 in words is "four hundred million, four hundred two thousand, five hundred sixty-one".