2661230056621 has 2 divisors, whose sum is σ = 2661230056622. Its totient is φ = 2661230056620.

The previous prime is 2661230056609. The next prime is 2661230056669. The reversal of 2661230056621 is 1266500321662.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2496207243721 + 165022812900 = 1579939^2 + 406230^2 .

It is a cyclic number.

It is not a de Polignac number, because 2661230056621 - 2³⁵ = 2626870318253 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2661230056921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1330615028310 + 1330615028311.

It is an arithmetic number, because the mean of its divisors is an integer number (1330615028311).

Almost surely, 2^{2661230056621} is an apocalyptic number.

It is an amenable number.

2661230056621 is a deficient number, since it is larger than the sum of its proper divisors (1).

2661230056621 is an equidigital number, since it uses as much as digits as its factorization.

2661230056621 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 155520, while the sum is 40.

The spelling of 2661230056621 in words is "two trillion, six hundred sixty-one billion, two hundred thirty million, fifty-six thousand, six hundred twenty-one".