8689781961 has 81 divisors (see below), whose sum is σ = 15343130439. Its totient is φ = 4725084672.

The previous prime is 8689781959. The next prime is 8689781977. The reversal of 8689781961 is 1691879868.

The square root of 8689781961 is 93219.

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

It can be written as a sum of positive squares in only one way, i.e., 2105433225 + 6584348736 = 45885^2 + 81144^2 .

It is not a de Polignac number, because 8689781961 - 2¹ = 8689781959 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is not an unprimeable number, because it can be changed into a prime (8689781981) by changing a digit.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 45024681 + ... + 45024873.

Almost surely, 2^8689781961 is an apocalyptic number.

8689781961 is the 93219-th square number.

8689781961 is the 46610-th centered octagonal number.

It is an amenable number.

8689781961 is a deficient number, since it is larger than the sum of its proper divisors (6653348478).

8689781961 is a wasteful number, since it uses less digits than its factorization.

8689781961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 452 (or 226 counting only the distinct ones).

The product of its digits is 10450944, while the sum is 63.

The cubic root of 8689781961 is about 2055.9046075068.

The spelling of 8689781961 in words is "eight billion, six hundred eighty-nine million, seven hundred eighty-one thousand, nine hundred sixty-one".