858989 has 2 divisors, whose sum is σ = 858990. Its totient is φ = 858988.

The previous prime is 858961. The next prime is 858997. The reversal of 858989 is 989858.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 855625 + 3364 = 925^2 + 58^2 .

It is a cyclic number.

It is not a de Polignac number, because 858989 - 2¹⁶ = 793453 is a prime.

It is an Ulam number.

It is an alternating number because its digits alternate between even and odd.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (858919) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 429494 + 429495.

It is an arithmetic number, because the mean of its divisors is an integer number (429495).

2⁸⁵⁸⁹⁸⁹ is an apocalyptic number.

It is an amenable number.

858989 is a deficient number, since it is larger than the sum of its proper divisors (1).

858989 is an equidigital number, since it uses as much as digits as its factorization.

858989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 207360, while the sum is 47.

The square root of 858989 is about 926.8165945860. The cubic root of 858989 is about 95.0595748210.

The spelling of 858989 in words is "eight hundred fifty-eight thousand, nine hundred eighty-nine".