400020431 has 12 divisors (see below), whose sum is σ = 419938848. Its totient is φ = 380866752.

The previous prime is 400020427. The next prime is 400020437. The reversal of 400020431 is 134020004.

It is not a de Polignac number, because 400020431 - 2² = 400020427 is a prime.

It is a super-2 number, since 2×400020431² = 320032690434851522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (400020437) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 61235 + ... + 67451.

It is an arithmetic number, because the mean of its divisors is an integer number (34994904).

Almost surely, 2^400020431 is an apocalyptic number.

400020431 is a deficient number, since it is larger than the sum of its proper divisors (19918417).

400020431 is an equidigital number, since it uses as much as digits as its factorization.

400020431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6338 (or 6301 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 14.

The square root of 400020431 is about 20000.5107684779. The cubic root of 400020431 is about 736.8188442558.

Adding to 400020431 its reverse (134020004), we get a palindrome (534040435).

The spelling of 400020431 in words is "four hundred million, twenty thousand, four hundred thirty-one".