978520638 has 8 divisors (see below), whose sum is σ = 1957041288. Its totient is φ = 326173544.

The previous prime is 978520633. The next prime is 978520657. The reversal of 978520638 is 836025879.

978520638 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

978520638 is an admirable number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (978520633) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 81543381 + ... + 81543392.

It is an arithmetic number, because the mean of its divisors is an integer number (244630161).

Almost surely, 2^978520638 is an apocalyptic number.

978520638 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

978520638 is a wasteful number, since it uses less digits than its factorization.

978520638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 163086778.

The product of its (nonzero) digits is 725760, while the sum is 48.

The square root of 978520638 is about 31281.3145184150. The cubic root of 978520638 is about 992.7883294972.

The spelling of 978520638 in words is "nine hundred seventy-eight million, five hundred twenty thousand, six hundred thirty-eight".