161020637 has 6 divisors (see below), whose sum is σ = 164521758. Its totient is φ = 157592504.

The previous prime is 161020627. The next prime is 161020661. The reversal of 161020637 is 736020161.

It can be written as a sum of positive squares in only one way, i.e., 91030681 + 69989956 = 9541^2 + 8366^2 .

It is a de Polignac number, because none of the positive numbers 2^k-161020637 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161020627) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 34238 + ... + 38655.

It is an arithmetic number, because the mean of its divisors is an integer number (27420293).

Almost surely, 2^161020637 is an apocalyptic number.

It is an amenable number.

161020637 is a deficient number, since it is larger than the sum of its proper divisors (3501121).

161020637 is an frugal number, since it uses more digits than its factorization.

161020637 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72987 (or 72940 counting only the distinct ones).

The product of its (nonzero) digits is 1512, while the sum is 26.

The square root of 161020637 is about 12689.3907261145. The cubic root of 161020637 is about 544.0354253981.

Adding to 161020637 its reverse (736020161), we get a palindrome (897040798).

The spelling of 161020637 in words is "one hundred sixty-one million, twenty thousand, six hundred thirty-seven".