21216572066730 has 32 divisors (see below), whose sum is σ = 50949849734784. Its totient is φ = 5654410687296.

The previous prime is 21216572066717. The next prime is 21216572066747. The reversal of 21216572066730 is 3766027561212.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21216572066730.

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, 208814854 + ... + 208916433.

It is an arithmetic number, because the mean of its divisors is an integer number (1592182804212).

Almost surely, 2^{21216572066730} is an apocalyptic number.

21216572066730 is an abundant number, since it is smaller than the sum of its proper divisors (29733277668054).

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

21216572066730 is a wasteful number, since it uses less digits than its factorization.

21216572066730 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 417732990.

The product of its (nonzero) digits is 1270080, while the sum is 48.

The spelling of 21216572066730 in words is "twenty-one trillion, two hundred sixteen billion, five hundred seventy-two million, sixty-six thousand, seven hundred thirty".