21231510371 has 2 divisors, whose sum is σ = 21231510372. Its totient is φ = 21231510370.

The previous prime is 21231510359. The next prime is 21231510389. The reversal of 21231510371 is 17301513212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21231510371 - 2²⁶ = 21164401507 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21231510371.

It is not a weakly prime, because it can be changed into another prime (21231510331) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10615755185 + 10615755186.

It is an arithmetic number, because the mean of its divisors is an integer number (10615755186).

Almost surely, 2^21231510371 is an apocalyptic number.

21231510371 is a deficient number, since it is larger than the sum of its proper divisors (1).

21231510371 is an equidigital number, since it uses as much as digits as its factorization.

21231510371 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1260, while the sum is 26.

The spelling of 21231510371 in words is "twenty-one billion, two hundred thirty-one million, five hundred ten thousand, three hundred seventy-one".