21361564630 has 32 divisors (see below), whose sum is σ = 45361336320. Its totient is φ = 7087707360.

The previous prime is 21361564607. The next prime is 21361564669. The reversal of 21361564630 is 3646516312.

It is a self number, because there is not a number n which added to its sum of digits gives 21361564630.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4919850 + ... + 4924189.

It is an arithmetic number, because the mean of its divisors is an integer number (1417541760).

Almost surely, 2^21361564630 is an apocalyptic number.

21361564630 is an abundant number, since it is smaller than the sum of its proper divisors (23999771690).

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

21361564630 is a wasteful number, since it uses less digits than its factorization.

21361564630 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9844084.

The product of its (nonzero) digits is 77760, while the sum is 37.

The spelling of 21361564630 in words is "twenty-one billion, three hundred sixty-one million, five hundred sixty-four thousand, six hundred thirty".