2656631621 has 16 divisors (see below), whose sum is σ = 3056330880. Its totient is φ = 2262024960.

The previous prime is 2656631611. The next prime is 2656631639. The reversal of 2656631621 is 1261366562.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 2656631621 - 2³⁰ = 1582889797 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 (2656631611) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 826265 + ... + 829473.

It is an arithmetic number, because the mean of its divisors is an integer number (191020680).

Almost surely, 2^2656631621 is an apocalyptic number.

It is an amenable number.

2656631621 is a deficient number, since it is larger than the sum of its proper divisors (399699259).

2656631621 is a wasteful number, since it uses less digits than its factorization.

2656631621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3964.

The product of its digits is 77760, while the sum is 38.

The square root of 2656631621 is about 51542.5224547654. The cubic root of 2656631621 is about 1384.9808841475.

The spelling of 2656631621 in words is "two billion, six hundred fifty-six million, six hundred thirty-one thousand, six hundred twenty-one".