6445993 has 2 divisors, whose sum is σ = 6445994. Its totient is φ = 6445992.

The previous prime is 6445991. The next prime is 6446017. The reversal of 6445993 is 3995446.

It is the 1037-th star number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6411024 + 34969 = 2532^2 + 187^2 .

It is a cyclic number.

It is not a de Polignac number, because 6445993 - 2¹ = 6445991 is a prime.

Together with 6445991, it forms a pair of twin primes.

6445993 is a lucky number.

It is not a weakly prime, because it can be changed into another prime (6445991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3222996 + 3222997.

It is an arithmetic number, because the mean of its divisors is an integer number (3222997).

Almost surely, 2^6445993 is an apocalyptic number.

It is an amenable number.

6445993 is a deficient number, since it is larger than the sum of its proper divisors (1).

6445993 is an equidigital number, since it uses as much as digits as its factorization.

6445993 is an evil number, because the sum of its binary digits is even.

The product of its digits is 116640, while the sum is 40.

The square root of 6445993 is about 2538.8960199268. The cubic root of 6445993 is about 186.1072434301.

The spelling of 6445993 in words is "six million, four hundred forty-five thousand, nine hundred ninety-three".