21310031051 has 2 divisors, whose sum is σ = 21310031052. Its totient is φ = 21310031050.

The previous prime is 21310031023. The next prime is 21310031059. The reversal of 21310031051 is 15013001312.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21310031051 is a prime.

It is not a weakly prime, because it can be changed into another prime (21310031059) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10655015525 + 10655015526.

It is an arithmetic number, because the mean of its divisors is an integer number (10655015526).

Almost surely, 2^21310031051 is an apocalyptic number.

21310031051 is a deficient number, since it is larger than the sum of its proper divisors (1).

21310031051 is an equidigital number, since it uses as much as digits as its factorization.

21310031051 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 90, while the sum is 17.

Adding to 21310031051 its reverse (15013001312), we get a palindrome (36323032363).

The spelling of 21310031051 in words is "twenty-one billion, three hundred ten million, thirty-one thousand, fifty-one".