225195971981 has 2 divisors, whose sum is σ = 225195971982. Its totient is φ = 225195971980.

The previous prime is 225195971933. The next prime is 225195971999. The reversal of 225195971981 is 189179591522.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 189652411081 + 35543560900 = 435491^2 + 188530^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-225195971981 is a prime.

It is a super-2 number, since 2×225195971981² (a number of 24 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 225195971981.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (225195971081) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 112597985990 + 112597985991.

It is an arithmetic number, because the mean of its divisors is an integer number (112597985991).

Almost surely, 2^225195971981 is an apocalyptic number.

It is an amenable number.

225195971981 is a deficient number, since it is larger than the sum of its proper divisors (1).

225195971981 is an equidigital number, since it uses as much as digits as its factorization.

225195971981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4082400, while the sum is 59.

The spelling of 225195971981 in words is "two hundred twenty-five billion, one hundred ninety-five million, nine hundred seventy-one thousand, nine hundred eighty-one".