978989534721 has 27 divisors (see below), whose sum is σ = 1554388762017. Its totient is φ = 593307201960.

The previous prime is 978989534659. The next prime is 978989534749. The reversal of 978989534721 is 127435989879.

The square root of 978989534721 is 989439.

It is a perfect power (a square), and thus also a powerful number.

978989534721 is a `hidden beast` number, since 9 + 7 + 8 + 9 + 89 + 534 + 7 + 2 + 1 = 666.

It is not a de Polignac number, because 978989534721 - 2⁹ = 978989534209 is a prime.

It is a Smith number, since the sum of its digits (72) coincides with the sum of the digits of its prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 978989534721.

It is not an unprimeable number, because it can be changed into a prime (978989534921) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 32636496 + ... + 32666478.

Almost surely, 2^978989534721 is an apocalyptic number.

978989534721 is the 989439-th square number.

978989534721 is the 494720-th centered octagonal number.

It is an amenable number.

978989534721 is a deficient number, since it is larger than the sum of its proper divisors (575399227296).

978989534721 is an frugal number, since it uses more digits than its factorization.

978989534721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 59994 (or 29997 counting only the distinct ones).

The product of its digits is 274337280, while the sum is 72.

The spelling of 978989534721 in words is "nine hundred seventy-eight billion, nine hundred eighty-nine million, five hundred thirty-four thousand, seven hundred twenty-one".