21122020057 has 2 divisors, whose sum is σ = 21122020058. Its totient is φ = 21122020056.

The previous prime is 21122020043. The next prime is 21122020181. The reversal of 21122020057 is 75002022112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21097853001 + 24167056 = 145251^2 + 4916^2 .

It is a cyclic number.

It is not a de Polignac number, because 21122020057 - 2²³ = 21113631449 is a prime.

It is a super-2 number, since 2×21122020057² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21122020037) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10561010028 + 10561010029.

It is an arithmetic number, because the mean of its divisors is an integer number (10561010029).

Almost surely, 2^21122020057 is an apocalyptic number.

It is an amenable number.

21122020057 is a deficient number, since it is larger than the sum of its proper divisors (1).

21122020057 is an equidigital number, since it uses as much as digits as its factorization.

21122020057 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 560, while the sum is 22.

Adding to 21122020057 its reverse (75002022112), we get a palindrome (96124042169).

The spelling of 21122020057 in words is "twenty-one billion, one hundred twenty-two million, twenty thousand, fifty-seven".