21115515515466 has 32 divisors (see below), whose sum is σ = 43028177349888. Its totient is φ = 6905649516480.

The previous prime is 21115515515441. The next prime is 21115515515467. The reversal of 21115515515466 is 66451551551112.

It is not an unprimeable number, because it can be changed into a prime (21115515515467) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 77646111 + ... + 77917581.

It is an arithmetic number, because the mean of its divisors is an integer number (1344630542184).

Almost surely, 2^{21115515515466} is an apocalyptic number.

21115515515466 is an abundant number, since it is smaller than the sum of its proper divisors (21912661834422).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21115515515466 is a wasteful number, since it uses less digits than its factorization.

21115515515466 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 516126.

The product of its digits is 900000, while the sum is 48.

The spelling of 21115515515466 in words is "twenty-one trillion, one hundred fifteen billion, five hundred fifteen million, five hundred fifteen thousand, four hundred sixty-six".