161617551994 has 8 divisors (see below), whose sum is σ = 242509845600. Its totient is φ = 80780936796.

The previous prime is 161617551973. The next prime is 161617552007. The reversal of 161617551994 is 499155716161.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×161617551994² (a number of 23 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13912344 + ... + 13923955.

It is an arithmetic number, because the mean of its divisors is an integer number (30313730700).

Almost surely, 2^161617551994 is an apocalyptic number.

161617551994 is a deficient number, since it is larger than the sum of its proper divisors (80892293606).

161617551994 is a wasteful number, since it uses less digits than its factorization.

161617551994 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27839204.

The product of its digits is 2041200, while the sum is 55.

The spelling of 161617551994 in words is "one hundred sixty-one billion, six hundred seventeen million, five hundred fifty-one thousand, nine hundred ninety-four".