21507527087 has 2 divisors, whose sum is σ = 21507527088. Its totient is φ = 21507527086.

The previous prime is 21507527077. The next prime is 21507527117. The reversal of 21507527087 is 78072570512.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21507527087 - 2¹⁸ = 21507264943 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21507527017) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10753763543 + 10753763544.

It is an arithmetic number, because the mean of its divisors is an integer number (10753763544).

Almost surely, 2^21507527087 is an apocalyptic number.

21507527087 is a deficient number, since it is larger than the sum of its proper divisors (1).

21507527087 is an equidigital number, since it uses as much as digits as its factorization.

21507527087 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 274400, while the sum is 44.

The spelling of 21507527087 in words is "twenty-one billion, five hundred seven million, five hundred twenty-seven thousand, eighty-seven".