2666125921 has 2 divisors, whose sum is σ = 2666125922. Its totient is φ = 2666125920.

The previous prime is 2666125879. The next prime is 2666125993. The reversal of 2666125921 is 1295216662.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1358291025 + 1307834896 = 36855^2 + 36164^2 .

It is a cyclic number.

It is not a de Polignac number, because 2666125921 - 2²⁵ = 2632571489 is a prime.

It is not a weakly prime, because it can be changed into another prime (2666125321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1333062960 + 1333062961.

It is an arithmetic number, because the mean of its divisors is an integer number (1333062961).

Almost surely, 2^2666125921 is an apocalyptic number.

It is an amenable number.

2666125921 is a deficient number, since it is larger than the sum of its proper divisors (1).

2666125921 is an equidigital number, since it uses as much as digits as its factorization.

2666125921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 77760, while the sum is 40.

The square root of 2666125921 is about 51634.5419365758. The cubic root of 2666125921 is about 1386.6288093387.

The spelling of 2666125921 in words is "two billion, six hundred sixty-six million, one hundred twenty-five thousand, nine hundred twenty-one".