616665161 has 4 divisors (see below), whose sum is σ = 704760192. Its totient is φ = 528570132.

The previous prime is 616665139. The next prime is 616665187. The reversal of 616665161 is 161566616.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 616665161 - 2⁶ = 616665097 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (616665661) 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, 44047505 + ... + 44047518.

It is an arithmetic number, because the mean of its divisors is an integer number (176190048).

Almost surely, 2^616665161 is an apocalyptic number.

It is an amenable number.

616665161 is a deficient number, since it is larger than the sum of its proper divisors (88095031).

616665161 is an equidigital number, since it uses as much as digits as its factorization.

616665161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 88095030.

The product of its digits is 38880, while the sum is 38.

The square root of 616665161 is about 24832.7437267814. The cubic root of 616665161 is about 851.1703191683.

The spelling of 616665161 in words is "six hundred sixteen million, six hundred sixty-five thousand, one hundred sixty-one".