400634509 has 6 divisors (see below), whose sum is σ = 440366990. Its totient is φ = 364213080.

The previous prime is 400634501. The next prime is 400634527. The reversal of 400634509 is 905436004.

It can be written as a sum of positive squares in only one way, i.e., 387696100 + 12938409 = 19690^2 + 3597^2 .

It is not a de Polignac number, because 400634509 - 2³ = 400634501 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (400634501) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1655394 + ... + 1655635.

Almost surely, 2^400634509 is an apocalyptic number.

It is an amenable number.

400634509 is a deficient number, since it is larger than the sum of its proper divisors (39732481).

400634509 is a wasteful number, since it uses less digits than its factorization.

400634509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3311051 (or 3311040 counting only the distinct ones).

The product of its (nonzero) digits is 12960, while the sum is 31.

The square root of 400634509 is about 20015.8564393333. The cubic root of 400634509 is about 737.1956857668.

The spelling of 400634509 in words is "four hundred million, six hundred thirty-four thousand, five hundred nine".