56999989 has 2 divisors, whose sum is σ = 56999990. Its totient is φ = 56999988.

The previous prime is 56999947. The next prime is 57000011. The reversal of 56999989 is 98999965.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 55011889 + 1988100 = 7417^2 + 1410^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-56999989 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 56999989.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (56999689) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 28499994 + 28499995.

It is an arithmetic number, because the mean of its divisors is an integer number (28499995).

Almost surely, 2^56999989 is an apocalyptic number.

It is an amenable number.

56999989 is a deficient number, since it is larger than the sum of its proper divisors (1).

56999989 is an equidigital number, since it uses as much as digits as its factorization.

56999989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 14171760, while the sum is 64.

The square root of 56999989 is about 7549.8337067779. The cubic root of 56999989 is about 384.8500883712.

The spelling of 56999989 in words is "fifty-six million, nine hundred ninety-nine thousand, nine hundred eighty-nine".