161668157 has 4 divisors (see below), whose sum is σ = 184763616. Its totient is φ = 138572700.

The previous prime is 161668153. The next prime is 161668159. The reversal of 161668157 is 751866161.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 751866161 = 67 ⋅11221883.

It is not a de Polignac number, because 161668157 - 2² = 161668153 is a prime.

It is a super-2 number, since 2×161668157² = 52273185975553298, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161668151) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11547719 + ... + 11547732.

It is an arithmetic number, because the mean of its divisors is an integer number (46190904).

Almost surely, 2^161668157 is an apocalyptic number.

It is an amenable number.

161668157 is a deficient number, since it is larger than the sum of its proper divisors (23095459).

161668157 is an equidigital number, since it uses as much as digits as its factorization.

161668157 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23095458.

The product of its digits is 60480, while the sum is 41.

The square root of 161668157 is about 12714.8793545200. The cubic root of 161668157 is about 544.7637019556.

The spelling of 161668157 in words is "one hundred sixty-one million, six hundred sixty-eight thousand, one hundred fifty-seven".