161880137 has 4 divisors (see below), whose sum is σ = 171402516. Its totient is φ = 152357760.

The previous prime is 161880119. The next prime is 161880139. The reversal of 161880137 is 731088161.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 731088161 = 11483 ⋅63667.

It can be written as a sum of positive squares in 2 ways, for example, as 68873401 + 93006736 = 8299^2 + 9644^2 .

It is a cyclic number.

It is not a de Polignac number, because 161880137 - 2²² = 157685833 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 161880097 and 161880106.

It is not an unprimeable number, because it can be changed into a prime (161880139) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4761164 + ... + 4761197.

It is an arithmetic number, because the mean of its divisors is an integer number (42850629).

Almost surely, 2^161880137 is an apocalyptic number.

161880137 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

It is an amenable number.

161880137 is a deficient number, since it is larger than the sum of its proper divisors (9522379).

161880137 is an equidigital number, since it uses as much as digits as its factorization.

161880137 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9522378.

The product of its (nonzero) digits is 8064, while the sum is 35.

The square root of 161880137 is about 12723.2125267167. The cubic root of 161880137 is about 545.0016968216.

The spelling of 161880137 in words is "one hundred sixty-one million, eight hundred eighty thousand, one hundred thirty-seven".