997693840 has 80 divisors (see below), whose sum is σ = 2725200576. Its totient is φ = 334886400.

The previous prime is 997693811. The next prime is 997693843. The reversal of 997693840 is 48396799.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (55).

It is not an unprimeable number, because it can be changed into a prime (997693843) 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 15 ways as a sum of consecutive naturals, for example, 32166 + ... + 55045.

Almost surely, 2^997693840 is an apocalyptic number.

It is an amenable number.

997693840 is an abundant number, since it is smaller than the sum of its proper divisors (1727506736).

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

997693840 is a wasteful number, since it uses less digits than its factorization.

997693840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 87248 (or 87242 counting only the distinct ones).

The product of its (nonzero) digits is 2939328, while the sum is 55.

The square root of 997693840 is about 31586.2919634452. The cubic root of 997693840 is about 999.2306883113.

The spelling of 997693840 in words is "nine hundred ninety-seven million, six hundred ninety-three thousand, eight hundred forty".