20400431232 has 32 divisors (see below), whose sum is σ = 54188646480. Its totient is φ = 6800143616.

The previous prime is 20400431231. The next prime is 20400431243. The reversal of 20400431232 is 23213400402.

It is a tau number, because it is divible by the number of its divisors (32).

It is a super-2 number, since 2×20400431232² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 20400431199 and 20400431208.

It is not an unprimeable number, because it can be changed into a prime (20400431231) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26562678 + ... + 26563445.

Almost surely, 2^20400431232 is an apocalyptic number.

It is an amenable number.

20400431232 is an abundant number, since it is smaller than the sum of its proper divisors (33788215248).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20400431232 is an equidigital number, since it uses as much as digits as its factorization.

20400431232 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53126140 (or 53126128 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 21.

Adding to 20400431232 its reverse (23213400402), we get a palindrome (43613831634).

The spelling of 20400431232 in words is "twenty billion, four hundred million, four hundred thirty-one thousand, two hundred thirty-two".