7878669561 has 96 divisors (see below), whose sum is σ = 14347673600. Its totient is φ = 4064670720.

The previous prime is 7878669559. The next prime is 7878669563. The reversal of 7878669561 is 1659668787.

7878669561 is a `hidden beast` number, since 7 + 8 + 7 + 8 + 6 + 69 + 561 = 666.

It is an interprime number because it is at equal distance from previous prime (7878669559) and next prime (7878669563).

It is not a de Polignac number, because 7878669561 - 2¹ = 7878669559 is a prime.

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

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (7878669563) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 2484585 + ... + 2487753.

Almost surely, 2^7878669561 is an apocalyptic number.

It is an amenable number.

7878669561 is a deficient number, since it is larger than the sum of its proper divisors (6469004039).

7878669561 is a wasteful number, since it uses less digits than its factorization.

7878669561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3299 (or 3296 counting only the distinct ones).

The product of its digits is 30481920, while the sum is 63.

The square root of 7878669561 is about 88761.8699724155. The cubic root of 7878669561 is about 1989.8375801549.

The spelling of 7878669561 in words is "seven billion, eight hundred seventy-eight million, six hundred sixty-nine thousand, five hundred sixty-one".