400512421 has 4 divisors (see below), whose sum is σ = 400611744. Its totient is φ = 400413100.

The previous prime is 400512403. The next prime is 400512461. The reversal of 400512421 is 124215004.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 400512421 - 2²³ = 392123813 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 (400512461) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 43345 + ... + 51766.

It is an arithmetic number, because the mean of its divisors is an integer number (100152936).

Almost surely, 2^400512421 is an apocalyptic number.

It is an amenable number.

400512421 is a deficient number, since it is larger than the sum of its proper divisors (99323).

400512421 is an equidigital number, since it uses as much as digits as its factorization.

400512421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 99322.

The product of its (nonzero) digits is 320, while the sum is 19.

The square root of 400512421 is about 20012.8064248870. The cubic root of 400512421 is about 737.1207946555.

Adding to 400512421 its reverse (124215004), we get a palindrome (524727425).

The spelling of 400512421 in words is "four hundred million, five hundred twelve thousand, four hundred twenty-one".