2668061621 has 4 divisors (see below), whose sum is σ = 2668164972. Its totient is φ = 2667958272.

The previous prime is 2668061581. The next prime is 2668061629. The reversal of 2668061621 is 1261608662.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 2355160900 + 312900721 = 48530^2 + 17689^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2668061621 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 (2668061629) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 23591 + ... + 76763.

It is an arithmetic number, because the mean of its divisors is an integer number (667041243).

Almost surely, 2^2668061621 is an apocalyptic number.

It is an amenable number.

2668061621 is a deficient number, since it is larger than the sum of its proper divisors (103351).

2668061621 is an equidigital number, since it uses as much as digits as its factorization.

2668061621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 103350.

The product of its (nonzero) digits is 41472, while the sum is 38.

The square root of 2668061621 is about 51653.2827707978. The cubic root of 2668061621 is about 1386.9643083793.

The spelling of 2668061621 in words is "two billion, six hundred sixty-eight million, sixty-one thousand, six hundred twenty-one".