978439483921 has 27 divisors (see below), whose sum is σ = 1060030925499. Its totient is φ = 903016946832.

The previous prime is 978439483883. The next prime is 978439483961. The reversal of 978439483921 is 129384934879.

The square root of 978439483921 is 989161.

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

978439483921 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 513069931521 + 465369552400 = 716289^2 + 682180^2 .

It is not a de Polignac number, because 978439483921 - 2⁷ = 978439483793 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (978439483961) 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, 659769646 + ... + 659771128.

Almost surely, 2^978439483921 is an apocalyptic number.

978439483921 is the 989161-st square number.

978439483921 is the 494581-st centered octagonal number.

It is an amenable number.

978439483921 is a deficient number, since it is larger than the sum of its proper divisors (81591441578).

978439483921 is an frugal number, since it uses more digits than its factorization.

978439483921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3070 (or 1535 counting only the distinct ones).

The product of its digits is 94058496, while the sum is 67.

The spelling of 978439483921 in words is "nine hundred seventy-eight billion, four hundred thirty-nine million, four hundred eighty-three thousand, nine hundred twenty-one".