2661556651 has 8 divisors (see below), whose sum is σ = 3017149520. Its totient is φ = 2327514912.

The previous prime is 2661556621. The next prime is 2661556661. The reversal of 2661556651 is 1566551662.

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 2661556651 - 2¹¹ = 2661554603 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2661556598 and 2661556607.

It is not an unprimeable number, because it can be changed into a prime (2661556621) 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, 5387520 + ... + 5388013.

It is an arithmetic number, because the mean of its divisors is an integer number (377143690).

Almost surely, 2^2661556651 is an apocalyptic number.

2661556651 is a deficient number, since it is larger than the sum of its proper divisors (355592869).

2661556651 is a wasteful number, since it uses less digits than its factorization.

2661556651 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10775565.

The product of its digits is 324000, while the sum is 43.

The square root of 2661556651 is about 51590.2767098607. The cubic root of 2661556651 is about 1385.8362105661.

The spelling of 2661556651 in words is "two billion, six hundred sixty-one million, five hundred fifty-six thousand, six hundred fifty-one".