5656878991 has 2 divisors, whose sum is σ = 5656878992. Its totient is φ = 5656878990.

The previous prime is 5656878847. The next prime is 5656879021. The reversal of 5656878991 is 1998786565.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 5656878991 - 2¹⁷ = 5656747919 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (5656878391) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2828439495 + 2828439496.

It is an arithmetic number, because the mean of its divisors is an integer number (2828439496).

Almost surely, 2^5656878991 is an apocalyptic number.

5656878991 is a deficient number, since it is larger than the sum of its proper divisors (1).

5656878991 is an equidigital number, since it uses as much as digits as its factorization.

5656878991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 32659200, while the sum is 64.

The square root of 5656878991 is about 75212.2263398711. The cubic root of 5656878991 is about 1781.8000339724.

The spelling of 5656878991 in words is "five billion, six hundred fifty-six million, eight hundred seventy-eight thousand, nine hundred ninety-one".