21580038145 has 4 divisors (see below), whose sum is σ = 25896045780. Its totient is φ = 17264030512.

The previous prime is 21580038133. The next prime is 21580038169. The reversal of 21580038145 is 54183008512.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 14334793984 + 7245244161 = 119728^2 + 85119^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21580038145 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2158003810 + ... + 2158003819.

It is an arithmetic number, because the mean of its divisors is an integer number (6474011445).

Almost surely, 2^21580038145 is an apocalyptic number.

It is an amenable number.

21580038145 is a deficient number, since it is larger than the sum of its proper divisors (4316007635).

21580038145 is an equidigital number, since it uses as much as digits as its factorization.

21580038145 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4316007634.

The product of its (nonzero) digits is 38400, while the sum is 37.

The spelling of 21580038145 in words is "twenty-one billion, five hundred eighty million, thirty-eight thousand, one hundred forty-five".