21722775557 has 4 divisors (see below), whose sum is σ = 24826029216. Its totient is φ = 18619521900.

The previous prime is 21722775551. The next prime is 21722775587. The reversal of 21722775557 is 75557722712.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 21722775557 - 2¹² = 21722771461 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21722775551) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1551626819 + ... + 1551626832.

It is an arithmetic number, because the mean of its divisors is an integer number (6206507304).

Almost surely, 2^21722775557 is an apocalyptic number.

It is an amenable number.

21722775557 is a deficient number, since it is larger than the sum of its proper divisors (3103253659).

21722775557 is an equidigital number, since it uses as much as digits as its factorization.

21722775557 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3103253658.

The product of its digits is 2401000, while the sum is 50.

The spelling of 21722775557 in words is "twenty-one billion, seven hundred twenty-two million, seven hundred seventy-five thousand, five hundred fifty-seven".