21250518338 has 16 divisors (see below), whose sum is σ = 36521231424. Its totient is φ = 9084422160.

The previous prime is 21250518329. The next prime is 21250518379. The reversal of 21250518338 is 83381505212.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1906148 + ... + 1917263.

It is an arithmetic number, because the mean of its divisors is an integer number (2282576964).

Almost surely, 2^21250518338 is an apocalyptic number.

21250518338 is a deficient number, since it is larger than the sum of its proper divisors (15270713086).

21250518338 is a wasteful number, since it uses less digits than its factorization.

21250518338 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3823817.

The product of its (nonzero) digits is 57600, while the sum is 38.

The spelling of 21250518338 in words is "twenty-one billion, two hundred fifty million, five hundred eighteen thousand, three hundred thirty-eight".