22157765621 has 4 divisors (see below), whose sum is σ = 22189832544. Its totient is φ = 22125698700.

The previous prime is 22157765569. The next prime is 22157765633. The reversal of 22157765621 is 12656775122.

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, and also an emirpimes, since its reverse is a distinct semiprime: 12656775122 = 2 ⋅6328387561.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-22157765621 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 (22157765671) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16032425 + ... + 16033806.

It is an arithmetic number, because the mean of its divisors is an integer number (5547458136).

Almost surely, 2^22157765621 is an apocalyptic number.

It is an amenable number.

22157765621 is a deficient number, since it is larger than the sum of its proper divisors (32066923).

22157765621 is an equidigital number, since it uses as much as digits as its factorization.

22157765621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32066922.

The product of its digits is 352800, while the sum is 44.

The spelling of 22157765621 in words is "twenty-two billion, one hundred fifty-seven million, seven hundred sixty-five thousand, six hundred twenty-one".