21174431231 has 8 divisors (see below), whose sum is σ = 22375607280. Its totient is φ = 19981928448.

The previous prime is 21174431191. The next prime is 21174431251. The reversal of 21174431231 is 13213447112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21174431231 - 2¹⁸ = 21174169087 is a prime.

It is a super-2 number, since 2×21174431231² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21174431194 and 21174431203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21174431251) 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, 2163296 + ... + 2173061.

It is an arithmetic number, because the mean of its divisors is an integer number (2796950910).

Almost surely, 2^21174431231 is an apocalyptic number.

21174431231 is a deficient number, since it is larger than the sum of its proper divisors (1201176049).

21174431231 is a wasteful number, since it uses less digits than its factorization.

21174431231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4336633.

The product of its digits is 4032, while the sum is 29.

Adding to 21174431231 its reverse (13213447112), we get a palindrome (34387878343).

The spelling of 21174431231 in words is "twenty-one billion, one hundred seventy-four million, four hundred thirty-one thousand, two hundred thirty-one".