21431430311 has 4 divisors (see below), whose sum is σ = 21438646824. Its totient is φ = 21424213800.

The previous prime is 21431430299. The next prime is 21431430329. The reversal of 21431430311 is 11303413412.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21431430311 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21431430211) 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, 3603800 + ... + 3609741.

It is an arithmetic number, because the mean of its divisors is an integer number (5359661706).

Almost surely, 2^21431430311 is an apocalyptic number.

21431430311 is a deficient number, since it is larger than the sum of its proper divisors (7216513).

21431430311 is an equidigital number, since it uses as much as digits as its factorization.

21431430311 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7216512.

The product of its (nonzero) digits is 864, while the sum is 23.

Adding to 21431430311 its reverse (11303413412), we get a palindrome (32734843723).

The spelling of 21431430311 in words is "twenty-one billion, four hundred thirty-one million, four hundred thirty thousand, three hundred eleven".