815389 has 2 divisors, whose sum is σ = 815390. Its totient is φ = 815388.

The previous prime is 815351. The next prime is 815401. The reversal of 815389 is 983518.

815389 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., 412164 + 403225 = 642^2 + 635^2 .

It is a cyclic number.

It is not a de Polignac number, because 815389 - 2⁷ = 815261 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (815989) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 407694 + 407695.

It is an arithmetic number, because the mean of its divisors is an integer number (407695).

2⁸¹⁵³⁸⁹ is an apocalyptic number.

It is an amenable number.

815389 is a deficient number, since it is larger than the sum of its proper divisors (1).

815389 is an equidigital number, since it uses as much as digits as its factorization.

815389 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8640, while the sum is 34.

The square root of 815389 is about 902.9889257350. The cubic root of 815389 is about 93.4232452723.

The spelling of 815389 in words is "eight hundred fifteen thousand, three hundred eighty-nine".