56821669 has 2 divisors, whose sum is σ = 56821670. Its totient is φ = 56821668.

The previous prime is 56821663. The next prime is 56821673. The reversal of 56821669 is 96612865.

56821669 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 56821444 + 225 = 7538^2 + 15^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-56821669 is a prime.

It is a super-2 number, since 2×56821669² = 6457404135891122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (56821663) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 28410834 + 28410835.

It is an arithmetic number, because the mean of its divisors is an integer number (28410835).

Almost surely, 2^56821669 is an apocalyptic number.

It is an amenable number.

56821669 is a deficient number, since it is larger than the sum of its proper divisors (1).

56821669 is an equidigital number, since it uses as much as digits as its factorization.

56821669 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 155520, while the sum is 43.

The square root of 56821669 is about 7538.0149243684. The cubic root of 56821669 is about 384.4483446880.

The spelling of 56821669 in words is "fifty-six million, eight hundred twenty-one thousand, six hundred sixty-nine".