161611507 has 4 divisors (see below), whose sum is σ = 161653936. Its totient is φ = 161569080.

The previous prime is 161611487. The next prime is 161611517. The reversal of 161611507 is 705116161.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 705116161 = 659 ⋅1069979.

It is a cyclic number.

It is not a de Polignac number, because 161611507 - 2⁷ = 161611379 is a prime.

It is a super-2 number, since 2×161611507² = 52236558389622098, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161611517) 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, 14868 + ... + 23329.

It is an arithmetic number, because the mean of its divisors is an integer number (40413484).

Almost surely, 2^161611507 is an apocalyptic number.

161611507 is a deficient number, since it is larger than the sum of its proper divisors (42429).

161611507 is an equidigital number, since it uses as much as digits as its factorization.

161611507 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42428.

The product of its (nonzero) digits is 1260, while the sum is 28.

The square root of 161611507 is about 12712.6514543584. The cubic root of 161611507 is about 544.7000644617.

Adding to 161611507 its reverse (705116161), we get a palindrome (866727668).

The spelling of 161611507 in words is "one hundred sixty-one million, six hundred eleven thousand, five hundred seven".