215389 has 2 divisors, whose sum is σ = 215390. Its totient is φ = 215388.

The previous prime is 215381. The next prime is 215393. The reversal of 215389 is 983512.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 209764 + 5625 = 458^2 + 75^2 .

It is a cyclic number.

It is not a de Polignac number, because 215389 - 2³ = 215381 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (215381) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 107694 + 107695.

It is an arithmetic number, because the mean of its divisors is an integer number (107695).

2²¹⁵³⁸⁹ is an apocalyptic number.

It is an amenable number.

215389 is a deficient number, since it is larger than the sum of its proper divisors (1).

215389 is an equidigital number, since it uses as much as digits as its factorization.

215389 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2160, while the sum is 28.

The square root of 215389 is about 464.1002046972. The cubic root of 215389 is about 59.9433724982.

The spelling of 215389 in words is "two hundred fifteen thousand, three hundred eighty-nine".