21267550321 has 8 divisors (see below), whose sum is σ = 21409970688. Its totient is φ = 21125454000.

The previous prime is 21267550319. The next prime is 21267550349. The reversal of 21267550321 is 12305576212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21267550321 - 2¹ = 21267550319 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21267550361) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 51411 + ... + 212551.

It is an arithmetic number, because the mean of its divisors is an integer number (2676246336).

Almost surely, 2^21267550321 is an apocalyptic number.

It is an amenable number.

21267550321 is a deficient number, since it is larger than the sum of its proper divisors (142420367).

21267550321 is a wasteful number, since it uses less digits than its factorization.

21267550321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 162023.

The product of its (nonzero) digits is 25200, while the sum is 34.

The spelling of 21267550321 in words is "twenty-one billion, two hundred sixty-seven million, five hundred fifty thousand, three hundred twenty-one".