21065555315 has 16 divisors (see below), whose sum is σ = 29039602368. Its totient is φ = 14370103296.

The previous prime is 21065555297. The next prime is 21065555327. The reversal of 21065555315 is 51355556012.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 21065555315 - 2²⁴ = 21048778099 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1552502 + ... + 1566011.

It is an arithmetic number, because the mean of its divisors is an integer number (1814975148).

Almost surely, 2^21065555315 is an apocalyptic number.

21065555315 is a deficient number, since it is larger than the sum of its proper divisors (7974047053).

21065555315 is a wasteful number, since it uses less digits than its factorization.

21065555315 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3118718.

The product of its (nonzero) digits is 112500, while the sum is 38.

The spelling of 21065555315 in words is "twenty-one billion, sixty-five million, five hundred fifty-five thousand, three hundred fifteen".