21136225897 has 2 divisors, whose sum is σ = 21136225898. Its totient is φ = 21136225896.

The previous prime is 21136225867. The next prime is 21136225907. The reversal of 21136225897 is 79852263112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19347697216 + 1788528681 = 139096^2 + 42291^2 .

It is a cyclic number.

It is not a de Polignac number, because 21136225897 - 2⁷ = 21136225769 is a prime.

It is not a weakly prime, because it can be changed into another prime (21136225837) 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 as a sum of consecutive naturals, namely, 10568112948 + 10568112949.

It is an arithmetic number, because the mean of its divisors is an integer number (10568112949).

Almost surely, 2^21136225897 is an apocalyptic number.

It is an amenable number.

21136225897 is a deficient number, since it is larger than the sum of its proper divisors (1).

21136225897 is an equidigital number, since it uses as much as digits as its factorization.

21136225897 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 362880, while the sum is 46.

The spelling of 21136225897 in words is "twenty-one billion, one hundred thirty-six million, two hundred twenty-five thousand, eight hundred ninety-seven".