21576084545 has 16 divisors (see below), whose sum is σ = 25960960080. Its totient is φ = 17214489600.

The previous prime is 21576084529. The next prime is 21576084583. The reversal of 21576084545 is 54548067512.

It is a Cunningham number, because it is equal to 146888²+1.

It can be written as a sum of positive squares in 8 ways, for example, as 1 + 21576084544 = 1^2 + 146888^2 .

It is not a de Polignac number, because 21576084545 - 2⁴ = 21576084529 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21576084545.

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, 3755375 + ... + 3761115.

It is an arithmetic number, because the mean of its divisors is an integer number (1622560005).

Almost surely, 2^21576084545 is an apocalyptic number.

It is an amenable number.

21576084545 is a deficient number, since it is larger than the sum of its proper divisors (4384875535).

21576084545 is a wasteful number, since it uses less digits than its factorization.

21576084545 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7636.

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

The spelling of 21576084545 in words is "twenty-one billion, five hundred seventy-six million, eighty-four thousand, five hundred forty-five".