161656087187 has 32 divisors (see below), whose sum is σ = 187274626560. Its totient is φ = 136684915200.

The previous prime is 161656087181. The next prime is 161656087189. The reversal of 161656087187 is 781780656161.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 161656087187 - 2¹² = 161656083091 is a prime.

It is a super-2 number, since 2×161656087187² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (161656087181) 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 31 ways as a sum of consecutive naturals, for example, 123684188 + ... + 123685494.

It is an arithmetic number, because the mean of its divisors is an integer number (5852332080).

Almost surely, 2^161656087187 is an apocalyptic number.

161656087187 is a deficient number, since it is larger than the sum of its proper divisors (25618539373).

161656087187 is a wasteful number, since it uses less digits than its factorization.

161656087187 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2171.

The product of its (nonzero) digits is 3386880, while the sum is 56.

The spelling of 161656087187 in words is "one hundred sixty-one billion, six hundred fifty-six million, eighty-seven thousand, one hundred eighty-seven".