21431131432 has 8 divisors (see below), whose sum is σ = 40183371450. Its totient is φ = 10715565712.

The previous prime is 21431131427. The next prime is 21431131441. The reversal of 21431131432 is 23413113412.

It can be written as a sum of positive squares in only one way, i.e., 20596268196 + 834863236 = 143514^2 + 28894^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a junction number, because it is equal to n+sod(n) for n = 21431131397 and 21431131406.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1339445707 + ... + 1339445722.

Almost surely, 2^21431131432 is an apocalyptic number.

It is an amenable number.

21431131432 is a deficient number, since it is larger than the sum of its proper divisors (18752240018).

21431131432 is a wasteful number, since it uses less digits than its factorization.

21431131432 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2678891435 (or 2678891431 counting only the distinct ones).

The product of its digits is 1728, while the sum is 25.

Adding to 21431131432 its reverse (23413113412), we get a palindrome (44844244844).

The spelling of 21431131432 in words is "twenty-one billion, four hundred thirty-one million, one hundred thirty-one thousand, four hundred thirty-two".