4947991 has 2 divisors, whose sum is σ = 4947992. Its totient is φ = 4947990.

The previous prime is 4947979. The next prime is 4948039. The reversal of 4947991 is 1997494.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 4947991 - 2⁵ = 4947959 is a prime.

It is a super-2 number, since 2×4947991² = 48965229872162, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (4947191) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2473995 + 2473996.

It is an arithmetic number, because the mean of its divisors is an integer number (2473996).

Almost surely, 2^4947991 is an apocalyptic number.

4947991 is a deficient number, since it is larger than the sum of its proper divisors (1).

4947991 is an equidigital number, since it uses as much as digits as its factorization.

4947991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 81648, while the sum is 43.

The square root of 4947991 is about 2224.4080111346. The cubic root of 4947991 is about 170.4026327225.

The spelling of 4947991 in words is "four million, nine hundred forty-seven thousand, nine hundred ninety-one".