997857878 has 8 divisors (see below), whose sum is σ = 1517290968. Its totient is φ = 492094224.

The previous prime is 997857869. The next prime is 997857907. The reversal of 997857878 is 878758799.

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

It is a congruent number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 3417176 + ... + 3417467.

It is an arithmetic number, because the mean of its divisors is an integer number (189661371).

Almost surely, 2^997857878 is an apocalyptic number.

997857878 is a deficient number, since it is larger than the sum of its proper divisors (519433090).

997857878 is a wasteful number, since it uses less digits than its factorization.

997857878 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6834718.

The product of its digits is 71124480, while the sum is 68.

The square root of 997857878 is about 31588.8885211240. Note that the first 3 decimals coincide. The cubic root of 997857878 is about 999.2854488716.

The spelling of 997857878 in words is "nine hundred ninety-seven million, eight hundred fifty-seven thousand, eight hundred seventy-eight".