21572628545 has 8 divisors (see below), whose sum is σ = 27878473896. Its totient is φ = 15930556416.

The previous prime is 21572628479. The next prime is 21572628551. The reversal of 21572628545 is 54582627512.

It can be written as a sum of positive squares in 4 ways, for example, as 3163837504 + 18408791041 = 56248^2 + 135679^2 .

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 21572628545 - 2²⁸ = 21304193089 is a prime.

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 21572628545.

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, 165943232 + ... + 165943361.

It is an arithmetic number, because the mean of its divisors is an integer number (3484809237).

Almost surely, 2^21572628545 is an apocalyptic number.

It is an amenable number.

21572628545 is a deficient number, since it is larger than the sum of its proper divisors (6305845351).

21572628545 is a wasteful number, since it uses less digits than its factorization.

21572628545 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 331886611.

The product of its digits is 1344000, while the sum is 47.

The spelling of 21572628545 in words is "twenty-one billion, five hundred seventy-two million, six hundred twenty-eight thousand, five hundred forty-five".