161511659 has 4 divisors (see below), whose sum is σ = 162187680. Its totient is φ = 160835640.

The previous prime is 161511653. The next prime is 161511661. The reversal of 161511659 is 956115161.

161511659 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 956115161 = 1181 ⋅809581.

It is a cyclic number.

It is not a de Polignac number, because 161511659 - 2⁸ = 161511403 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161511653) 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, 337652 + ... + 338129.

It is an arithmetic number, because the mean of its divisors is an integer number (40546920).

Almost surely, 2^161511659 is an apocalyptic number.

161511659 is a deficient number, since it is larger than the sum of its proper divisors (676021).

161511659 is an equidigital number, since it uses as much as digits as its factorization.

161511659 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 676020.

The product of its digits is 8100, while the sum is 35.

The square root of 161511659 is about 12708.7237360799. The cubic root of 161511659 is about 544.5878644962.

The spelling of 161511659 in words is "one hundred sixty-one million, five hundred eleven thousand, six hundred fifty-nine".