2656611021 has 12 divisors (see below), whose sum is σ = 3702852608. Its totient is φ = 1694069784.

The previous prime is 2656611017. The next prime is 2656611049. The reversal of 2656611021 is 1201166562.

It is not a de Polignac number, because 2656611021 - 2² = 2656611017 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 2656611021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2656611011) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 835405 + ... + 838578.

Almost surely, 2^2656611021 is an apocalyptic number.

It is an amenable number.

2656611021 is a deficient number, since it is larger than the sum of its proper divisors (1046241587).

2656611021 is a wasteful number, since it uses less digits than its factorization.

2656611021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1674032 (or 1674009 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 30.

The square root of 2656611021 is about 51542.3226193776. The cubic root of 2656611021 is about 1384.9773043412.

Adding to 2656611021 its reverse (1201166562), we get a palindrome (3857777583).

The spelling of 2656611021 in words is "two billion, six hundred fifty-six million, six hundred eleven thousand, twenty-one".