2195351981 has 2 divisors, whose sum is σ = 2195351982. Its totient is φ = 2195351980.

The previous prime is 2195351953. The next prime is 2195351989. The reversal of 2195351981 is 1891535912.

2195351981 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1230255625 + 965096356 = 35075^2 + 31066^2 .

It is a cyclic number.

It is not a de Polignac number, because 2195351981 - 2²² = 2191157677 is a prime.

It is a super-2 number, since 2×2195351981² = 9639140640961248722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2195351989) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1097675990 + 1097675991.

It is an arithmetic number, because the mean of its divisors is an integer number (1097675991).

Almost surely, 2^2195351981 is an apocalyptic number.

It is an amenable number.

2195351981 is a deficient number, since it is larger than the sum of its proper divisors (1).

2195351981 is an equidigital number, since it uses as much as digits as its factorization.

2195351981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 97200, while the sum is 44.

The square root of 2195351981 is about 46854.5833510448. The cubic root of 2195351981 is about 1299.6748656324.

The spelling of 2195351981 in words is "two billion, one hundred ninety-five million, three hundred fifty-one thousand, nine hundred eighty-one".