2691787661 has 8 divisors (see below), whose sum is σ = 2711148000. Its totient is φ = 2672444880.

The previous prime is 2691787649. The next prime is 2691787669. The reversal of 2691787661 is 1667871962.

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

It is a cyclic number.

It is not a de Polignac number, because 2691787661 - 2⁶ = 2691787597 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 (2691787669) 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, 529550 + ... + 534608.

It is an arithmetic number, because the mean of its divisors is an integer number (338893500).

Almost surely, 2^2691787661 is an apocalyptic number.

It is an amenable number.

2691787661 is a deficient number, since it is larger than the sum of its proper divisors (19360339).

2691787661 is a wasteful number, since it uses less digits than its factorization.

2691787661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8779.

The product of its digits is 1524096, while the sum is 53.

The square root of 2691787661 is about 51882.4407772032. The cubic root of 2691787661 is about 1391.0634273652.

The spelling of 2691787661 in words is "two billion, six hundred ninety-one million, seven hundred eighty-seven thousand, six hundred sixty-one".