161681732 has 6 divisors (see below), whose sum is σ = 282943038. Its totient is φ = 80840864.

The previous prime is 161681719. The next prime is 161681791. The reversal of 161681732 is 237186161.

It can be written as a sum of positive squares in only one way, i.e., 106832896 + 54848836 = 10336^2 + 7406^2 .

It is a super-2 number, since 2×161681732² = 52281964925039648, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 161681692 and 161681701.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20210213 + ... + 20210220.

It is an arithmetic number, because the mean of its divisors is an integer number (47157173).

Almost surely, 2^161681732 is an apocalyptic number.

It is an amenable number.

161681732 is a deficient number, since it is larger than the sum of its proper divisors (121261306).

161681732 is a wasteful number, since it uses less digits than its factorization.

161681732 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40420437 (or 40420435 counting only the distinct ones).

The product of its digits is 12096, while the sum is 35.

The square root of 161681732 is about 12715.4131667044. The cubic root of 161681732 is about 544.7789491558.

The spelling of 161681732 in words is "one hundred sixty-one million, six hundred eighty-one thousand, seven hundred thirty-two".