161722137 has 8 divisors (see below), whose sum is σ = 216005536. Its totient is φ = 107626752.

The previous prime is 161722117. The next prime is 161722157. The reversal of 161722137 is 731227161.

It is an interprime number because it is at equal distance from previous prime (161722117) and next prime (161722157).

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

It is not a de Polignac number, because 161722137 - 2⁸ = 161721881 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161722117) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 44983 + ... + 48444.

It is an arithmetic number, because the mean of its divisors is an integer number (27000692).

Almost surely, 2^161722137 is an apocalyptic number.

It is an amenable number.

161722137 is a deficient number, since it is larger than the sum of its proper divisors (54283399).

161722137 is an equidigital number, since it uses as much as digits as its factorization.

161722137 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 94007.

The product of its digits is 3528, while the sum is 30.

The square root of 161722137 is about 12717.0018872374. The cubic root of 161722137 is about 544.8243262882.

Adding to 161722137 its reverse (731227161), we get a palindrome (892949298).

The spelling of 161722137 in words is "one hundred sixty-one million, seven hundred twenty-two thousand, one hundred thirty-seven".