997802191 has 8 divisors (see below), whose sum is σ = 1005962400. Its totient is φ = 989661792.

The previous prime is 997802171. The next prime is 997802203. The reversal of 997802191 is 191208799.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 997802191 - 2¹⁹ = 997277903 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 (997802161) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 106201 + ... + 115213.

It is an arithmetic number, because the mean of its divisors is an integer number (125745300).

Almost surely, 2^997802191 is an apocalyptic number.

997802191 is the 16885-th centered heptagonal number.

997802191 is a deficient number, since it is larger than the sum of its proper divisors (8160209).

997802191 is a wasteful number, since it uses less digits than its factorization.

997802191 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9905.

The product of its (nonzero) digits is 81648, while the sum is 46.

The square root of 997802191 is about 31588.0070754709. The cubic root of 997802191 is about 999.2668596366.

The spelling of 997802191 in words is "nine hundred ninety-seven million, eight hundred two thousand, one hundred ninety-one".