161072122991 has 16 divisors (see below), whose sum is σ = 176432256000. Its totient is φ = 146157758208.

The previous prime is 161072122987. The next prime is 161072123029. The reversal of 161072122991 is 199221270161.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 161072122991 - 2² = 161072122987 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161072124991) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 267566 + ... + 627483.

It is an arithmetic number, because the mean of its divisors is an integer number (11027016000).

Almost surely, 2^161072122991 is an apocalyptic number.

161072122991 is a deficient number, since it is larger than the sum of its proper divisors (15360133009).

161072122991 is a wasteful number, since it uses less digits than its factorization.

161072122991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 895298.

The product of its (nonzero) digits is 27216, while the sum is 41.

The spelling of 161072122991 in words is "one hundred sixty-one billion, seventy-two million, one hundred twenty-two thousand, nine hundred ninety-one".