16613031661 has 4 divisors (see below), whose sum is σ = 16618378300. Its totient is φ = 16607685024.

The previous prime is 16613031647. The next prime is 16613031689.

16613031661 is nontrivially palindromic in base 10.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 2262429225 + 14350602436 = 47565^2 + 119794^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16613031661 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16613031761) 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, 2668656 + ... + 2674873.

It is an arithmetic number, because the mean of its divisors is an integer number (4154594575).

Almost surely, 2^16613031661 is an apocalyptic number.

It is an amenable number.

16613031661 is a deficient number, since it is larger than the sum of its proper divisors (5346639).

16613031661 is an equidigital number, since it uses as much as digits as its factorization.

16613031661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5346638.

The product of its (nonzero) digits is 11664, while the sum is 34.

It can be divided in two parts, 166130 and 31661, that added together give a palindrome (197791).

The spelling of 16613031661 in words is "sixteen billion, six hundred thirteen million, thirty-one thousand, six hundred sixty-one".