675445721 has 2 divisors, whose sum is σ = 675445722. Its totient is φ = 675445720.

The previous prime is 675445703. The next prime is 675445723. The reversal of 675445721 is 127544576.

675445721 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., 634485721 + 40960000 = 25189^2 + 6400^2 .

It is a cyclic number.

It is not a de Polignac number, because 675445721 - 2⁶ = 675445657 is a prime.

Together with 675445723, 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 (675445723) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 337722860 + 337722861.

It is an arithmetic number, because the mean of its divisors is an integer number (337722861).

Almost surely, 2^675445721 is an apocalyptic number.

It is an amenable number.

675445721 is a deficient number, since it is larger than the sum of its proper divisors (1).

675445721 is an equidigital number, since it uses as much as digits as its factorization.

675445721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 235200, while the sum is 41.

The square root of 675445721 is about 25989.3386025886. The cubic root of 675445721 is about 877.3983598858.

The spelling of 675445721 in words is "six hundred seventy-five million, four hundred forty-five thousand, seven hundred twenty-one".