215213989 has 2 divisors, whose sum is σ = 215213990. Its totient is φ = 215213988.

The previous prime is 215213981. The next prime is 215214047. The reversal of 215213989 is 989312512.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 211469764 + 3744225 = 14542^2 + 1935^2 .

It is a cyclic number.

It is not a de Polignac number, because 215213989 - 2³ = 215213981 is a prime.

It is a super-2 number, since 2×215213989² = 92634122122584242, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (215213981) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 107606994 + 107606995.

It is an arithmetic number, because the mean of its divisors is an integer number (107606995).

Almost surely, 2^215213989 is an apocalyptic number.

It is an amenable number.

215213989 is a deficient number, since it is larger than the sum of its proper divisors (1).

215213989 is an equidigital number, since it uses as much as digits as its factorization.

215213989 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 38880, while the sum is 40.

The square root of 215213989 is about 14670.1734481907. The cubic root of 215213989 is about 599.2713274558.

The spelling of 215213989 in words is "two hundred fifteen million, two hundred thirteen thousand, nine hundred eighty-nine".