21578179445 has 48 divisors (see below), whose sum is σ = 28942151040. Its totient is φ = 15372390528.

The previous prime is 21578179429. The next prime is 21578179451. The reversal of 21578179445 is 54497187512.

It is a happy number.

It is not a de Polignac number, because 21578179445 - 2⁴ = 21578179429 is a prime.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 7604567 + ... + 7607403.

It is an arithmetic number, because the mean of its divisors is an integer number (602961480).

Almost surely, 2^21578179445 is an apocalyptic number.

It is an amenable number.

21578179445 is a deficient number, since it is larger than the sum of its proper divisors (7363971595).

21578179445 is a wasteful number, since it uses less digits than its factorization.

21578179445 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3002 (or 2943 counting only the distinct ones).

The product of its digits is 2822400, while the sum is 53.

The spelling of 21578179445 in words is "twenty-one billion, five hundred seventy-eight million, one hundred seventy-nine thousand, four hundred forty-five".