161636437 has 4 divisors (see below), whose sum is σ = 161884620. Its totient is φ = 161388256.

The previous prime is 161636413. The next prime is 161636467. The reversal of 161636437 is 734636161.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 72692676 + 88943761 = 8526^2 + 9431^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-161636437 is a prime.

It is a super-2 number, since 2×161636437² = 52252675532109938, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 161636396 and 161636405.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161636407) 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, 123112 + ... + 124417.

It is an arithmetic number, because the mean of its divisors is an integer number (40471155).

Almost surely, 2^161636437 is an apocalyptic number.

It is an amenable number.

161636437 is a deficient number, since it is larger than the sum of its proper divisors (248183).

161636437 is an equidigital number, since it uses as much as digits as its factorization.

161636437 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 248182.

The product of its digits is 54432, while the sum is 37.

The square root of 161636437 is about 12713.6319358396. The cubic root of 161636437 is about 544.7280712843.

The spelling of 161636437 in words is "one hundred sixty-one million, six hundred thirty-six thousand, four hundred thirty-seven".