6996721 has 2 divisors, whose sum is σ = 6996722. Its totient is φ = 6996720.

The previous prime is 6996713. The next prime is 6996733. The reversal of 6996721 is 1276996.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6964321 + 32400 = 2639^2 + 180^2 .

It is a cyclic number.

It is not a de Polignac number, because 6996721 - 2³ = 6996713 is a prime.

It is a Chen prime.

6996721 is a lucky number.

It is not a weakly prime, because it can be changed into another prime (6996701) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3498360 + 3498361.

It is an arithmetic number, because the mean of its divisors is an integer number (3498361).

Almost surely, 2^6996721 is an apocalyptic number.

It is an amenable number.

6996721 is a deficient number, since it is larger than the sum of its proper divisors (1).

6996721 is an equidigital number, since it uses as much as digits as its factorization.

6996721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 40824, while the sum is 40.

The square root of 6996721 is about 2645.1315657260. The cubic root of 6996721 is about 191.2632445581.

The spelling of 6996721 in words is "six million, nine hundred ninety-six thousand, seven hundred twenty-one".