21655010519 has 2 divisors, whose sum is σ = 21655010520. Its totient is φ = 21655010518.

The previous prime is 21655010501. The next prime is 21655010539. The reversal of 21655010519 is 91501055612.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21655010519 - 2²⁰ = 21653961943 is a prime.

It is a super-2 number, since 2×21655010519² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21655010539) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10827505259 + 10827505260.

It is an arithmetic number, because the mean of its divisors is an integer number (10827505260).

Almost surely, 2^21655010519 is an apocalyptic number.

21655010519 is a deficient number, since it is larger than the sum of its proper divisors (1).

21655010519 is an equidigital number, since it uses as much as digits as its factorization.

21655010519 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 13500, while the sum is 35.

The spelling of 21655010519 in words is "twenty-one billion, six hundred fifty-five million, ten thousand, five hundred nineteen".