218397919 has 2 divisors, whose sum is σ = 218397920. Its totient is φ = 218397918.

The previous prime is 218397889. The next prime is 218397937. The reversal of 218397919 is 919793812.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 218397919 - 2¹¹ = 218395871 is a prime.

It is a super-2 number, since 2×218397919² = 95395302047061122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (218397979) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 109198959 + 109198960.

It is an arithmetic number, because the mean of its divisors is an integer number (109198960).

Almost surely, 2^218397919 is an apocalyptic number.

218397919 is a deficient number, since it is larger than the sum of its proper divisors (1).

218397919 is an equidigital number, since it uses as much as digits as its factorization.

218397919 is an evil number, because the sum of its binary digits is even.

The product of its digits is 244944, while the sum is 49.

The square root of 218397919 is about 14778.2921543729. The cubic root of 218397919 is about 602.2121294857.

The spelling of 218397919 in words is "two hundred eighteen million, three hundred ninety-seven thousand, nine hundred nineteen".