21131434432 has 14 divisors (see below), whose sum is σ = 41932690328. Its totient is φ = 10565717184.

The previous prime is 21131434417. The next prime is 21131434433. The reversal of 21131434432 is 23443413112.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 21131434432.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21131434433) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 165089268 + ... + 165089395.

Almost surely, 2^21131434432 is an apocalyptic number.

It is an amenable number.

21131434432 is a deficient number, since it is larger than the sum of its proper divisors (20801255896).

21131434432 is an equidigital number, since it uses as much as digits as its factorization.

21131434432 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 330178675 (or 330178665 counting only the distinct ones).

The product of its digits is 6912, while the sum is 28.

Adding to 21131434432 its reverse (23443413112), we get a palindrome (44574847544).

The spelling of 21131434432 in words is "twenty-one billion, one hundred thirty-one million, four hundred thirty-four thousand, four hundred thirty-two".