997825578 has 16 divisors (see below), whose sum is σ = 2042062176. Its totient is φ = 324873360.

The previous prime is 997825571. The next prime is 997825607. The reversal of 997825578 is 875528799.

It is a super-2 number, since 2×997825578² = 1991311768222068168, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (997825571) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 1933513 + ... + 1934028.

It is an arithmetic number, because the mean of its divisors is an integer number (127628886).

Almost surely, 2^997825578 is an apocalyptic number.

997825578 is an abundant number, since it is smaller than the sum of its proper divisors (1044236598).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

997825578 is a wasteful number, since it uses less digits than its factorization.

997825578 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3867589.

The product of its digits is 12700800, while the sum is 60.

The square root of 997825578 is about 31588.3772612649. The cubic root of 997825578 is about 999.2746666855.

The spelling of 997825578 in words is "nine hundred ninety-seven million, eight hundred twenty-five thousand, five hundred seventy-eight".