21083989231 has 2 divisors, whose sum is σ = 21083989232. Its totient is φ = 21083989230.

The previous prime is 21083989229. The next prime is 21083989243. The reversal of 21083989231 is 13298938012.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21083989231 - 2¹ = 21083989229 is a prime.

It is a super-2 number, since 2×21083989231² (a number of 21 digits) contains 22 as substring.

Together with 21083989229, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21083981231) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10541994615 + 10541994616.

It is an arithmetic number, because the mean of its divisors is an integer number (10541994616).

Almost surely, 2^21083989231 is an apocalyptic number.

21083989231 is a deficient number, since it is larger than the sum of its proper divisors (1).

21083989231 is an equidigital number, since it uses as much as digits as its factorization.

21083989231 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 186624, while the sum is 46.

The spelling of 21083989231 in words is "twenty-one billion, eighty-three million, nine hundred eighty-nine thousand, two hundred thirty-one".