21157773658523 has 2 divisors, whose sum is σ = 21157773658524. Its totient is φ = 21157773658522.

The previous prime is 21157773658519. The next prime is 21157773658579. The reversal of 21157773658523 is 32585637775112.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21157773658523 - 2² = 21157773658519 is a prime.

It is not a weakly prime, because it can be changed into another prime (21157773658223) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10578886829261 + 10578886829262.

It is an arithmetic number, because the mean of its divisors is an integer number (10578886829262).

Almost surely, 2^{21157773658523} is an apocalyptic number.

21157773658523 is a deficient number, since it is larger than the sum of its proper divisors (1).

21157773658523 is an equidigital number, since it uses as much as digits as its factorization.

21157773658523 is an evil number, because the sum of its binary digits is even.

The product of its digits is 74088000, while the sum is 62.

The spelling of 21157773658523 in words is "twenty-one trillion, one hundred fifty-seven billion, seven hundred seventy-three million, six hundred fifty-eight thousand, five hundred twenty-three".