21334402431 has 8 divisors (see below), whose sum is σ = 31606522160. Its totient is φ = 14222934936.

The previous prime is 21334402379. The next prime is 21334402489. The reversal of 21334402431 is 13420443312.

21334402431 is a `hidden beast` number, since 213 + 3 + 4 + 402 + 43 + 1 = 666.

It is not a de Polignac number, because 21334402431 - 2⁶ = 21334402367 is a prime.

It is a super-2 number, since 2×21334402431² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 790163053 = 21334402431 / (2 + 1 + 3 + 3 + 4 + 4 + 0 + 2 + 4 + 3 + 1).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21334402395 and 21334402404.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21334400431) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 395081500 + ... + 395081553.

It is an arithmetic number, because the mean of its divisors is an integer number (3950815270).

Almost surely, 2^21334402431 is an apocalyptic number.

21334402431 is a deficient number, since it is larger than the sum of its proper divisors (10272119729).

21334402431 is an equidigital number, since it uses as much as digits as its factorization.

21334402431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 790163062 (or 790163056 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 27.

Adding to 21334402431 its reverse (13420443312), we get a palindrome (34754845743).

The spelling of 21334402431 in words is "twenty-one billion, three hundred thirty-four million, four hundred two thousand, four hundred thirty-one".