161121686431 has 2 divisors, whose sum is σ = 161121686432. Its totient is φ = 161121686430.

The previous prime is 161121686333. The next prime is 161121686443. The reversal of 161121686431 is 134686121161.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 161121686431 - 2²³ = 161113297823 is a prime.

It is a super-2 number, since 2×161121686431² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (161121680431) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80560843215 + 80560843216.

It is an arithmetic number, because the mean of its divisors is an integer number (80560843216).

Almost surely, 2^161121686431 is an apocalyptic number.

161121686431 is a deficient number, since it is larger than the sum of its proper divisors (1).

161121686431 is an equidigital number, since it uses as much as digits as its factorization.

161121686431 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 41472, while the sum is 40.

The spelling of 161121686431 in words is "one hundred sixty-one billion, one hundred twenty-one million, six hundred eighty-six thousand, four hundred thirty-one".