216972839 has 2 divisors, whose sum is σ = 216972840. Its totient is φ = 216972838.

The previous prime is 216972827. The next prime is 216972841. The reversal of 216972839 is 938279612.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 216972839 - 2⁸ = 216972583 is a prime.

Together with 216972841, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 216972793 and 216972802.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (216972859) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108486419 + 108486420.

It is an arithmetic number, because the mean of its divisors is an integer number (108486420).

Almost surely, 2^216972839 is an apocalyptic number.

216972839 is a deficient number, since it is larger than the sum of its proper divisors (1).

216972839 is an equidigital number, since it uses as much as digits as its factorization.

216972839 is an evil number, because the sum of its binary digits is even.

The product of its digits is 326592, while the sum is 47.

The square root of 216972839 is about 14729.9979293956. The cubic root of 216972839 is about 600.8994278939.

The spelling of 216972839 in words is "two hundred sixteen million, nine hundred seventy-two thousand, eight hundred thirty-nine".