21122515087 has 2 divisors, whose sum is σ = 21122515088. Its totient is φ = 21122515086.

The previous prime is 21122515049. The next prime is 21122515091. The reversal of 21122515087 is 78051522112.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21122515087 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21122515097) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10561257543 + 10561257544.

It is an arithmetic number, because the mean of its divisors is an integer number (10561257544).

Almost surely, 2^21122515087 is an apocalyptic number.

21122515087 is a deficient number, since it is larger than the sum of its proper divisors (1).

21122515087 is an equidigital number, since it uses as much as digits as its factorization.

21122515087 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 11200, while the sum is 34.

The spelling of 21122515087 in words is "twenty-one billion, one hundred twenty-two million, five hundred fifteen thousand, eighty-seven".