978999440 has 40 divisors (see below), whose sum is σ = 2291275968. Its totient is φ = 389001600.

The previous prime is 978999421. The next prime is 978999443. The reversal of 978999440 is 44999879.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (40).

It is a self number, because there is not a number n which added to its sum of digits gives 978999440.

It is not an unprimeable number, because it can be changed into a prime (978999443) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 28442 + ... + 52601.

Almost surely, 2^978999440 is an apocalyptic number.

It is an amenable number.

978999440 is an abundant number, since it is smaller than the sum of its proper divisors (1312276528).

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

978999440 is a wasteful number, since it uses less digits than its factorization.

978999440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 81207 (or 81201 counting only the distinct ones).

The product of its (nonzero) digits is 5878656, while the sum is 59.

The square root of 978999440 is about 31288.9667454839. The cubic root of 978999440 is about 992.9502308781.

The spelling of 978999440 in words is "nine hundred seventy-eight million, nine hundred ninety-nine thousand, four hundred forty".