1625068721 has 2 divisors, whose sum is σ = 1625068722. Its totient is φ = 1625068720.

The previous prime is 1625068717. The next prime is 1625068723. The reversal of 1625068721 is 1278605261.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1574502400 + 50566321 = 39680^2 + 7111^2 .

It is a cyclic number.

It is not a de Polignac number, because 1625068721 - 2² = 1625068717 is a prime.

Together with 1625068723, 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 (1625068723) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 812534360 + 812534361.

It is an arithmetic number, because the mean of its divisors is an integer number (812534361).

Almost surely, 2^1625068721 is an apocalyptic number.

It is an amenable number.

1625068721 is a deficient number, since it is larger than the sum of its proper divisors (1).

1625068721 is an equidigital number, since it uses as much as digits as its factorization.

1625068721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 40320, while the sum is 38.

The square root of 1625068721 is about 40312.1411115808. The cubic root of 1625068721 is about 1175.6839165571.

The spelling of 1625068721 in words is "one billion, six hundred twenty-five million, sixty-eight thousand, seven hundred twenty-one".