216989131 has 2 divisors, whose sum is σ = 216989132. Its totient is φ = 216989130.

The previous prime is 216989111. The next prime is 216989183. The reversal of 216989131 is 131989612.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 216989131 - 2⁵ = 216989099 is a prime.

It is a super-2 number, since 2×216989131² = 94168565944270322, which contains 22 as substring.

It is a Chen prime.

It is equal to p_11965855 and since 216989131 and 11965855 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (216989111) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108494565 + 108494566.

It is an arithmetic number, because the mean of its divisors is an integer number (108494566).

Almost surely, 2^216989131 is an apocalyptic number.

216989131 is a deficient number, since it is larger than the sum of its proper divisors (1).

216989131 is an equidigital number, since it uses as much as digits as its factorization.

216989131 is an evil number, because the sum of its binary digits is even.

The product of its digits is 23328, while the sum is 40.

The square root of 216989131 is about 14730.5509401380. The cubic root of 216989131 is about 600.9144675774.

The spelling of 216989131 in words is "two hundred sixteen million, nine hundred eighty-nine thousand, one hundred thirty-one".