161311938225 has 12 divisors (see below), whose sum is σ = 266702404656. Its totient is φ = 86033033680.

The previous prime is 161311938217. The next prime is 161311938257. The reversal of 161311938225 is 522839113161.

It is a happy number.

It is not a de Polignac number, because 161311938225 - 2³ = 161311938217 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1075412847 + ... + 1075412996.

It is an arithmetic number, because the mean of its divisors is an integer number (22225200388).

Almost surely, 2^161311938225 is an apocalyptic number.

161311938225 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

161311938225 is a deficient number, since it is larger than the sum of its proper divisors (105390466431).

161311938225 is a wasteful number, since it uses less digits than its factorization.

161311938225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2150825856 (or 2150825851 counting only the distinct ones).

The product of its digits is 77760, while the sum is 42.

The spelling of 161311938225 in words is "one hundred sixty-one billion, three hundred eleven million, nine hundred thirty-eight thousand, two hundred twenty-five".