21122031197 has 2 divisors, whose sum is σ = 21122031198. Its totient is φ = 21122031196.

The previous prime is 21122031179. The next prime is 21122031277. The reversal of 21122031197 is 79113022112.

Together with previous prime (21122031179) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18493008121 + 2629023076 = 135989^2 + 51274^2 .

It is a cyclic number.

It is not a de Polignac number, because 21122031197 - 2²⁰ = 21120982621 is a prime.

It is a super-2 number, since 2×21122031197² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21122031107) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10561015598 + 10561015599.

It is an arithmetic number, because the mean of its divisors is an integer number (10561015599).

Almost surely, 2^21122031197 is an apocalyptic number.

It is an amenable number.

21122031197 is a deficient number, since it is larger than the sum of its proper divisors (1).

21122031197 is an equidigital number, since it uses as much as digits as its factorization.

21122031197 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1512, while the sum is 29.

The spelling of 21122031197 in words is "twenty-one billion, one hundred twenty-two million, thirty-one thousand, one hundred ninety-seven".