195444721 has 2 divisors, whose sum is σ = 195444722. Its totient is φ = 195444720.

The previous prime is 195444713. The next prime is 195444727. The reversal of 195444721 is 127444591.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 143041600 + 52403121 = 11960^2 + 7239^2 .

It is a cyclic number.

It is not a de Polignac number, because 195444721 - 2³ = 195444713 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (195444727) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 97722360 + 97722361.

It is an arithmetic number, because the mean of its divisors is an integer number (97722361).

Almost surely, 2^195444721 is an apocalyptic number.

It is an amenable number.

195444721 is a deficient number, since it is larger than the sum of its proper divisors (1).

195444721 is an equidigital number, since it uses as much as digits as its factorization.

195444721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 40320, while the sum is 37.

The square root of 195444721 is about 13980.1545413490. The cubic root of 195444721 is about 580.3295006453.

The spelling of 195444721 in words is "one hundred ninety-five million, four hundred forty-four thousand, seven hundred twenty-one".