21757788578 has 8 divisors (see below), whose sum is σ = 32674503168. Its totient is φ = 10866287524.

The previous prime is 21757788539. The next prime is 21757788581. The reversal of 21757788578 is 87588775712.

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

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, 6301226 + ... + 6304677.

It is an arithmetic number, because the mean of its divisors is an integer number (4084312896).

Almost surely, 2^21757788578 is an apocalyptic number.

21757788578 is a deficient number, since it is larger than the sum of its proper divisors (10916714590).

21757788578 is a wasteful number, since it uses less digits than its factorization.

21757788578 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12606768.

The product of its digits is 61465600, while the sum is 65.

The spelling of 21757788578 in words is "twenty-one billion, seven hundred fifty-seven million, seven hundred eighty-eight thousand, five hundred seventy-eight".