21512926087 has 2 divisors, whose sum is σ = 21512926088. Its totient is φ = 21512926086.

The previous prime is 21512926079. The next prime is 21512926093. The reversal of 21512926087 is 78062921512.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21512926087 - 2³ = 21512926079 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21512926027) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10756463043 + 10756463044.

It is an arithmetic number, because the mean of its divisors is an integer number (10756463044).

Almost surely, 2^21512926087 is an apocalyptic number.

21512926087 is a deficient number, since it is larger than the sum of its proper divisors (1).

21512926087 is an equidigital number, since it uses as much as digits as its factorization.

21512926087 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 120960, while the sum is 43.

The spelling of 21512926087 in words is "twenty-one billion, five hundred twelve million, nine hundred twenty-six thousand, eighty-seven".