56666689 has 2 divisors, whose sum is σ = 56666690. Its totient is φ = 56666688.

The previous prime is 56666681. The next prime is 56666693. The reversal of 56666689 is 98666665.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 34904464 + 21762225 = 5908^2 + 4665^2 .

It is a cyclic number.

It is not a de Polignac number, because 56666689 - 2³ = 56666681 is a prime.

It is a super-2 number, since 2×56666689² = 6422227284445442, which contains 22 as substring.

It is a plaindrome in base 10.

It is not a weakly prime, because it can be changed into another prime (56666681) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 28333344 + 28333345.

It is an arithmetic number, because the mean of its divisors is an integer number (28333345).

Almost surely, 2^56666689 is an apocalyptic number.

It is an amenable number.

56666689 is a deficient number, since it is larger than the sum of its proper divisors (1).

56666689 is an equidigital number, since it uses as much as digits as its factorization.

56666689 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2799360, while the sum is 52.

The square root of 56666689 is about 7527.7280104956. The cubic root of 56666689 is about 384.0985012970.

The spelling of 56666689 in words is "fifty-six million, six hundred sixty-six thousand, six hundred eighty-nine".