400811811409 has 27 divisors (see below), whose sum is σ = 430270115547. Its totient is φ = 373294250304.

The previous prime is 400811811397. The next prime is 400811811467. The reversal of 400811811409 is 904118118004.

The square root of 400811811409 is 633097.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 312050718225 + 88761093184 = 558615^2 + 297928^2 .

It is not a de Polignac number, because 400811811409 - 2⁵ = 400811811377 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (400811811479) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 1797362272 + ... + 1797362494.

Almost surely, 2^400811811409 is an apocalyptic number.

400811811409 is the 633097-th square number.

400811811409 is the 316549-th centered octagonal number.

It is an amenable number.

400811811409 is a deficient number, since it is larger than the sum of its proper divisors (29458304138).

400811811409 is an frugal number, since it uses more digits than its factorization.

400811811409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 814 (or 407 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 37.

The spelling of 400811811409 in words is "four hundred billion, eight hundred eleven million, eight hundred eleven thousand, four hundred nine".