997864919 has 4 divisors (see below), whose sum is σ = 1006695696. Its totient is φ = 989034144.

The previous prime is 997864909. The next prime is 997864937. The reversal of 997864919 is 919468799.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 997864919 - 2⁸ = 997864663 is a prime.

It is a super-2 number, since 2×997864919² = 1991468793141753122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (997864909) 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, 4415219 + ... + 4415444.

It is an arithmetic number, because the mean of its divisors is an integer number (251673924).

Almost surely, 2^997864919 is an apocalyptic number.

997864919 is a deficient number, since it is larger than the sum of its proper divisors (8830777).

997864919 is a wasteful number, since it uses less digits than its factorization.

997864919 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8830776.

The product of its digits is 8817984, while the sum is 62.

The square root of 997864919 is about 31588.9999683434. Note that the first 4 decimals coincide. The cubic root of 997864919 is about 999.2877992238.

The spelling of 997864919 in words is "nine hundred ninety-seven million, eight hundred sixty-four thousand, nine hundred nineteen".