971984561 has 16 divisors (see below), whose sum is σ = 1046907600. Its totient is φ = 900523008.

The previous prime is 971984549. The next prime is 971984567. The reversal of 971984561 is 165489179.

It can be written as a sum of positive squares in 8 ways, for example, as 1288225 + 970696336 = 1135^2 + 31156^2 .

It is a cyclic number.

It is not a de Polignac number, because 971984561 - 2¹⁴ = 971968177 is a prime.

It is not an unprimeable number, because it can be changed into a prime (971984567) 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 15 ways as a sum of consecutive naturals, for example, 72125 + ... + 84533.

It is an arithmetic number, because the mean of its divisors is an integer number (65431725).

Almost surely, 2^971984561 is an apocalyptic number.

It is an amenable number.

971984561 is a deficient number, since it is larger than the sum of its proper divisors (74923039).

971984561 is a wasteful number, since it uses less digits than its factorization.

971984561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12548.

The product of its digits is 544320, while the sum is 50.

The square root of 971984561 is about 31176.6669321786. Note that the first 3 decimals coincide. The cubic root of 971984561 is about 990.5729299436.

The spelling of 971984561 in words is "nine hundred seventy-one million, nine hundred eighty-four thousand, five hundred sixty-one".