216155389 has 2 divisors, whose sum is σ = 216155390. Its totient is φ = 216155388.

The previous prime is 216155383. The next prime is 216155399. The reversal of 216155389 is 983551612.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 177342489 + 38812900 = 13317^2 + 6230^2 .

It is a cyclic number.

It is not a de Polignac number, because 216155389 - 2²³ = 207766781 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (216155383) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108077694 + 108077695.

It is an arithmetic number, because the mean of its divisors is an integer number (108077695).

Almost surely, 2^216155389 is an apocalyptic number.

It is an amenable number.

216155389 is a deficient number, since it is larger than the sum of its proper divisors (1).

216155389 is an equidigital number, since it uses as much as digits as its factorization.

216155389 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 64800, while the sum is 40.

The square root of 216155389 is about 14702.2239474169. The cubic root of 216155389 is about 600.1438442157.

The spelling of 216155389 in words is "two hundred sixteen million, one hundred fifty-five thousand, three hundred eighty-nine".