41997778721 has 2 divisors, whose sum is σ = 41997778722. Its totient is φ = 41997778720.

The previous prime is 41997778687. The next prime is 41997778723. The reversal of 41997778721 is 12787779914.

41997778721 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 27238201600 + 14759577121 = 165040^2 + 121489^2 .

It is a cyclic number.

It is not a de Polignac number, because 41997778721 - 2¹⁰ = 41997777697 is a prime.

Together with 41997778723, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (41997778723) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20998889360 + 20998889361.

It is an arithmetic number, because the mean of its divisors is an integer number (20998889361).

Almost surely, 2^41997778721 is an apocalyptic number.

It is an amenable number.

41997778721 is a deficient number, since it is larger than the sum of its proper divisors (1).

41997778721 is an equidigital number, since it uses as much as digits as its factorization.

41997778721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 12446784, while the sum is 62.

The spelling of 41997778721 in words is "forty-one billion, nine hundred ninety-seven million, seven hundred seventy-eight thousand, seven hundred twenty-one".