16615651661 has 8 divisors (see below), whose sum is σ = 18990264384. Its totient is φ = 14241276000.

The previous prime is 16615651649. The next prime is 16615651687.

16615651661 is nontrivially palindromic in base 10.

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

It is not a de Polignac number, because 16615651661 - 2⁶ = 16615651597 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16615651631) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 132161 + ... + 225161.

It is an arithmetic number, because the mean of its divisors is an integer number (2373783048).

Almost surely, 2^16615651661 is an apocalyptic number.

It is an amenable number.

16615651661 is a deficient number, since it is larger than the sum of its proper divisors (2374612723).

16615651661 is an equidigital number, since it uses as much as digits as its factorization.

16615651661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 118531.

The product of its digits is 194400, while the sum is 44.

The spelling of 16615651661 in words is "sixteen billion, six hundred fifteen million, six hundred fifty-one thousand, six hundred sixty-one".