161640539 has 8 divisors (see below), whose sum is σ = 171259920. Its totient is φ = 152033536.

The previous prime is 161640529. The next prime is 161640587. The reversal of 161640539 is 935046161.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 161640539 - 2¹⁶ = 161575003 is a prime.

It is a super-2 number, since 2×161640539² = 52255327696421042, 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 = 161640499 and 161640508.

It is not an unprimeable number, because it can be changed into a prime (161640529) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 48767 + ... + 51975.

It is an arithmetic number, because the mean of its divisors is an integer number (21407490).

Almost surely, 2^161640539 is an apocalyptic number.

161640539 is a deficient number, since it is larger than the sum of its proper divisors (9619381).

161640539 is a wasteful number, since it uses less digits than its factorization.

161640539 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6189.

The product of its (nonzero) digits is 19440, while the sum is 35.

The square root of 161640539 is about 12713.7932577182. The cubic root of 161640539 is about 544.7326792710.

The spelling of 161640539 in words is "one hundred sixty-one million, six hundred forty thousand, five hundred thirty-nine".