161874637 has 4 divisors (see below), whose sum is σ = 161900316. Its totient is φ = 161848960.

The previous prime is 161874577. The next prime is 161874673. The reversal of 161874637 is 736478161.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 736478161 = 137 ⋅5375753.

It can be written as a sum of positive squares in 2 ways, for example, as 81252196 + 80622441 = 9014^2 + 8979^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-161874637 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 161874593 and 161874602.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161874677) 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, 3837 + ... + 18397.

It is an arithmetic number, because the mean of its divisors is an integer number (40475079).

Almost surely, 2^161874637 is an apocalyptic number.

It is an amenable number.

161874637 is a deficient number, since it is larger than the sum of its proper divisors (25679).

161874637 is a wasteful number, since it uses less digits than its factorization.

161874637 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25678.

The product of its digits is 169344, while the sum is 43.

The square root of 161874637 is about 12722.9963845000. The cubic root of 161874637 is about 544.9955244702.

The spelling of 161874637 in words is "one hundred sixty-one million, eight hundred seventy-four thousand, six hundred thirty-seven".