254664721021 has 2 divisors, whose sum is σ = 254664721022. Its totient is φ = 254664721020.

The previous prime is 254664721013. The next prime is 254664721037. The reversal of 254664721021 is 120127466452.

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., 140951439225 + 113713281796 = 375435^2 + 337214^2 .

It is a cyclic number.

It is not a de Polignac number, because 254664721021 - 2³ = 254664721013 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (254664721621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 127332360510 + 127332360511.

It is an arithmetic number, because the mean of its divisors is an integer number (127332360511).

Almost surely, 2^254664721021 is an apocalyptic number.

It is an amenable number.

254664721021 is a deficient number, since it is larger than the sum of its proper divisors (1).

254664721021 is an equidigital number, since it uses as much as digits as its factorization.

254664721021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 161280, while the sum is 40.

The spelling of 254664721021 in words is "two hundred fifty-four billion, six hundred sixty-four million, seven hundred twenty-one thousand, twenty-one".