997440578 has 4 divisors (see below), whose sum is σ = 1496160870. Its totient is φ = 498720288.

The previous prime is 997440569. The next prime is 997440629. The reversal of 997440578 is 875044799.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 875044799 = 163 ⋅5368373.

It can be written as a sum of positive squares in only one way, i.e., 871843729 + 125596849 = 29527^2 + 11207^2 .

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 as a sum of consecutive naturals, namely, 249360143 + ... + 249360146.

Almost surely, 2^997440578 is an apocalyptic number.

997440578 is a deficient number, since it is larger than the sum of its proper divisors (498720292).

997440578 is a wasteful number, since it uses less digits than its factorization.

997440578 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 498720291.

The product of its (nonzero) digits is 2540160, while the sum is 53.

The square root of 997440578 is about 31582.2826597445. The cubic root of 997440578 is about 999.1461304476.

The spelling of 997440578 in words is "nine hundred ninety-seven million, four hundred forty thousand, five hundred seventy-eight".