21395779355 has 32 divisors (see below), whose sum is σ = 26992828800. Its totient is φ = 16258278400.

The previous prime is 21395779351. The next prime is 21395779367. The reversal of 21395779355 is 55397759312.

It is not a de Polignac number, because 21395779355 - 2² = 21395779351 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21395779355.

It is not an unprimeable number, because it can be changed into a prime (21395779351) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 5361701 + ... + 5365689.

It is an arithmetic number, because the mean of its divisors is an integer number (843525900).

Almost surely, 2^21395779355 is an apocalyptic number.

21395779355 is a deficient number, since it is larger than the sum of its proper divisors (5597049445).

21395779355 is a wasteful number, since it uses less digits than its factorization.

21395779355 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4615.

The product of its digits is 8930250, while the sum is 56.

The spelling of 21395779355 in words is "twenty-one billion, three hundred ninety-five million, seven hundred seventy-nine thousand, three hundred fifty-five".