997286391 has 32 divisors (see below), whose sum is σ = 1501187520. Its totient is φ = 654262272.

The previous prime is 997286387. The next prime is 997286393. The reversal of 997286391 is 193682799.

It is not a de Polignac number, because 997286391 - 2² = 997286387 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (997286393) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 504481 + ... + 506453.

It is an arithmetic number, because the mean of its divisors is an integer number (46912110).

Almost surely, 2^997286391 is an apocalyptic number.

997286391 is a deficient number, since it is larger than the sum of its proper divisors (503901129).

997286391 is a wasteful number, since it uses less digits than its factorization.

997286391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2272 (or 2266 counting only the distinct ones).

The product of its digits is 1469664, while the sum is 54.

The square root of 997286391 is about 31579.8415290514. The cubic root of 997286391 is about 999.0946442450.

The spelling of 997286391 in words is "nine hundred ninety-seven million, two hundred eighty-six thousand, three hundred ninety-one".