25222211981 has 2 divisors, whose sum is σ = 25222211982. Its totient is φ = 25222211980.

The previous prime is 25222211957. The next prime is 25222212089. The reversal of 25222211981 is 18911222252.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 25203150025 + 19061956 = 158755^2 + 4366^2 .

It is a cyclic number.

It is not a de Polignac number, because 25222211981 - 2²² = 25218017677 is a prime.

It is a super-2 number, since 2×25222211981² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25222211281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12611105990 + 12611105991.

It is an arithmetic number, because the mean of its divisors is an integer number (12611105991).

Almost surely, 2^25222211981 is an apocalyptic number.

It is an amenable number.

25222211981 is a deficient number, since it is larger than the sum of its proper divisors (1).

25222211981 is an equidigital number, since it uses as much as digits as its factorization.

25222211981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 11520, while the sum is 35.

The spelling of 25222211981 in words is "twenty-five billion, two hundred twenty-two million, two hundred eleven thousand, nine hundred eighty-one".