2791218661 has 32 divisors (see below), whose sum is σ = 3699447552. Its totient is φ = 2038824960.

The previous prime is 2791218653. The next prime is 2791218671. The reversal of 2791218661 is 1668121972.

It is not a de Polignac number, because 2791218661 - 2³ = 2791218653 is a prime.

It is a super-2 number, since 2×2791218661² = 15581803227029265842, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2791218611) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 332265 + ... + 340561.

It is an arithmetic number, because the mean of its divisors is an integer number (115607736).

Almost surely, 2^2791218661 is an apocalyptic number.

It is an amenable number.

2791218661 is a deficient number, since it is larger than the sum of its proper divisors (908228891).

2791218661 is a wasteful number, since it uses less digits than its factorization.

2791218661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8589.

The product of its digits is 72576, while the sum is 43.

The square root of 2791218661 is about 52831.9852078265. The cubic root of 2791218661 is about 1407.9847576919.

It can be divided in two parts, 279121 and 8661, that added together give a palindrome (287782).

The spelling of 2791218661 in words is "two billion, seven hundred ninety-one million, two hundred eighteen thousand, six hundred sixty-one".