2991997 has 4 divisors (see below), whose sum is σ = 2995996. Its totient is φ = 2988000.

The previous prime is 2991971. The next prime is 2992007. The reversal of 2991997 is 7991992.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 2134521 + 857476 = 1461^2 + 926^2 .

It is a cyclic number.

It is not a de Polignac number, because 2991997 - 2¹⁹ = 2467709 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2991907) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 504 + ... + 2497.

It is an arithmetic number, because the mean of its divisors is an integer number (748999).

2^2991997 is an apocalyptic number.

It is an amenable number.

2991997 is a deficient number, since it is larger than the sum of its proper divisors (3999).

2991997 is an equidigital number, since it uses as much as digits as its factorization.

2991997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3998.

The product of its digits is 91854, while the sum is 46.

The square root of 2991997 is about 1729.7389976525. The cubic root of 2991997 is about 144.0965947836.

The spelling of 2991997 in words is "two million, nine hundred ninety-one thousand, nine hundred ninety-seven".