216138919 has 2 divisors, whose sum is σ = 216138920. Its totient is φ = 216138918.

The previous prime is 216138907. The next prime is 216138961. The reversal of 216138919 is 919831612.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 216138919 - 2²⁵ = 182584487 is a prime.

It is a super-2 number, since 2×216138919² = 93432064612977122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (216132919) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108069459 + 108069460.

It is an arithmetic number, because the mean of its divisors is an integer number (108069460).

Almost surely, 2^216138919 is an apocalyptic number.

216138919 is a deficient number, since it is larger than the sum of its proper divisors (1).

216138919 is an equidigital number, since it uses as much as digits as its factorization.

216138919 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 216138919 is about 14701.6638174052. The cubic root of 216138919 is about 600.1286011380.

The spelling of 216138919 in words is "two hundred sixteen million, one hundred thirty-eight thousand, nine hundred nineteen".