39942372161 has 2 divisors, whose sum is σ = 39942372162. Its totient is φ = 39942372160.

The previous prime is 39942372143. The next prime is 39942372167. The reversal of 39942372161 is 16127324993.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 38742442561 + 1199929600 = 196831^2 + 34640^2 .

It is a cyclic number.

It is not a de Polignac number, because 39942372161 - 2²² = 39938177857 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (39942372167) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19971186080 + 19971186081.

It is an arithmetic number, because the mean of its divisors is an integer number (19971186081).

Almost surely, 2^39942372161 is an apocalyptic number.

It is an amenable number.

39942372161 is a deficient number, since it is larger than the sum of its proper divisors (1).

39942372161 is an equidigital number, since it uses as much as digits as its factorization.

39942372161 is an evil number, because the sum of its binary digits is even.

The product of its digits is 489888, while the sum is 47.

The spelling of 39942372161 in words is "thirty-nine billion, nine hundred forty-two million, three hundred seventy-two thousand, one hundred sixty-one".