16783512661 has 4 divisors (see below), whose sum is σ = 16915666432. Its totient is φ = 16651358892.

The previous prime is 16783512659. The next prime is 16783512679. The reversal of 16783512661 is 16621538761.

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 16783512661 - 2¹ = 16783512659 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 (16783512601) 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, 66076695 + ... + 66076948.

It is an arithmetic number, because the mean of its divisors is an integer number (4228916608).

Almost surely, 2^16783512661 is an apocalyptic number.

It is an amenable number.

16783512661 is a deficient number, since it is larger than the sum of its proper divisors (132153771).

16783512661 is a wasteful number, since it uses less digits than its factorization.

16783512661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 132153770.

The product of its digits is 362880, while the sum is 46.

The spelling of 16783512661 in words is "sixteen billion, seven hundred eighty-three million, five hundred twelve thousand, six hundred sixty-one".