21157773658579 has 2 divisors, whose sum is σ = 21157773658580. Its totient is φ = 21157773658578.

The previous prime is 21157773658523. The next prime is 21157773658633. The reversal of 21157773658579 is 97585637775112.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21157773658579 - 2³¹ = 21155626174931 is a prime.

It is a super-3 number, since 3×21157773658579³ (a number of 41 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (21157773658519) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10578886829289 + 10578886829290.

It is an arithmetic number, because the mean of its divisors is an integer number (10578886829290).

Almost surely, 2^{21157773658579} is an apocalyptic number.

21157773658579 is a deficient number, since it is larger than the sum of its proper divisors (1).

21157773658579 is an equidigital number, since it uses as much as digits as its factorization.

21157773658579 is an evil number, because the sum of its binary digits is even.

The product of its digits is 777924000, while the sum is 73.

The spelling of 21157773658579 in words is "twenty-one trillion, one hundred fifty-seven billion, seven hundred seventy-three million, six hundred fifty-eight thousand, five hundred seventy-nine".