971978985 has 12 divisors (see below), whose sum is σ = 1684763652. Its totient is φ = 518388768.

The previous prime is 971978981. The next prime is 971979017. The reversal of 971978985 is 589879179.

It can be written as a sum of positive squares in 2 ways, for example, as 110439081 + 861539904 = 10509^2 + 29352^2 .

It is not a de Polignac number, because 971978985 - 2² = 971978981 is a prime.

It is not an unprimeable number, because it can be changed into a prime (971978981) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 10799722 + ... + 10799811.

It is an arithmetic number, because the mean of its divisors is an integer number (140396971).

Almost surely, 2^971978985 is an apocalyptic number.

It is an amenable number.

971978985 is a deficient number, since it is larger than the sum of its proper divisors (712784667).

971978985 is a wasteful number, since it uses less digits than its factorization.

971978985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21599544 (or 21599541 counting only the distinct ones).

The product of its digits is 11430720, while the sum is 63.

The square root of 971978985 is about 31176.5775061985. The cubic root of 971978985 is about 990.5710357279.

The spelling of 971978985 in words is "nine hundred seventy-one million, nine hundred seventy-eight thousand, nine hundred eighty-five".