2177904426721 has 2 divisors, whose sum is σ = 2177904426722. Its totient is φ = 2177904426720.

The previous prime is 2177904426707. The next prime is 2177904426727. The reversal of 2177904426721 is 1276244097712.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1877338425600 + 300566001121 = 1370160^2 + 548239^2 .

It is a cyclic number.

It is not a de Polignac number, because 2177904426721 - 2²³ = 2177896038113 is a prime.

It is not a weakly prime, because it can be changed into another prime (2177904426727) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1088952213360 + 1088952213361.

It is an arithmetic number, because the mean of its divisors is an integer number (1088952213361).

Almost surely, 2^{2177904426721} is an apocalyptic number.

It is an amenable number.

2177904426721 is a deficient number, since it is larger than the sum of its proper divisors (1).

2177904426721 is an equidigital number, since it uses as much as digits as its factorization.

2177904426721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2370816, while the sum is 52.

The spelling of 2177904426721 in words is "two trillion, one hundred seventy-seven billion, nine hundred four million, four hundred twenty-six thousand, seven hundred twenty-one".