6991541 has 2 divisors, whose sum is σ = 6991542. Its totient is φ = 6991540.

The previous prime is 6991531. The next prime is 6991549. The reversal of 6991541 is 1451996.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 5880625 + 1110916 = 2425^2 + 1054^2 .

It is a cyclic number.

It is not a de Polignac number, because 6991541 - 2¹⁰ = 6990517 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6991549) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3495770 + 3495771.

It is an arithmetic number, because the mean of its divisors is an integer number (3495771).

Almost surely, 2^6991541 is an apocalyptic number.

It is an amenable number.

6991541 is a deficient number, since it is larger than the sum of its proper divisors (1).

6991541 is an equidigital number, since it uses as much as digits as its factorization.

6991541 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9720, while the sum is 35.

The square root of 6991541 is about 2644.1522270853. The cubic root of 6991541 is about 191.2160325281.

The spelling of 6991541 in words is "six million, nine hundred ninety-one thousand, five hundred forty-one".