997194557 has 4 divisors (see below), whose sum is σ = 997281180. Its totient is φ = 997107936.

The previous prime is 997194547. The next prime is 997194563. The reversal of 997194557 is 755491799.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 755491799 = 67 ⋅11275997.

It can be written as a sum of positive squares in 2 ways, for example, as 615734596 + 381459961 = 24814^2 + 19531^2 .

It is a cyclic number.

It is not a de Polignac number, because 997194557 - 2²⁴ = 980417341 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 (997194547) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22808 + ... + 50145.

It is an arithmetic number, because the mean of its divisors is an integer number (249320295).

Almost surely, 2^997194557 is an apocalyptic number.

It is an amenable number.

997194557 is a deficient number, since it is larger than the sum of its proper divisors (86623).

997194557 is a wasteful number, since it uses less digits than its factorization.

997194557 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 86622.

The product of its digits is 3572100, while the sum is 56.

The square root of 997194557 is about 31578.3874984142. The cubic root of 997194557 is about 999.0639764666.

The spelling of 997194557 in words is "nine hundred ninety-seven million, one hundred ninety-four thousand, five hundred fifty-seven".