161857198 has 8 divisors (see below), whose sum is σ = 243108792. Its totient is φ = 80820936.

The previous prime is 161857183. The next prime is 161857229. The reversal of 161857198 is 891758161.

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

It is a super-2 number, since 2×161857198² = 52395505088822408, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 51940 + ... + 54967.

It is an arithmetic number, because the mean of its divisors is an integer number (30388599).

Almost surely, 2^161857198 is an apocalyptic number.

161857198 is a deficient number, since it is larger than the sum of its proper divisors (81251594).

161857198 is a wasteful number, since it uses less digits than its factorization.

161857198 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 107666.

The product of its digits is 120960, while the sum is 46.

The square root of 161857198 is about 12722.3110321985. The cubic root of 161857198 is about 544.9759527027.

The spelling of 161857198 in words is "one hundred sixty-one million, eight hundred fifty-seven thousand, one hundred ninety-eight".