218398919 has 4 divisors (see below), whose sum is σ = 218510496. Its totient is φ = 218287344.

The previous prime is 218398909. The next prime is 218398933. The reversal of 218398919 is 919893812.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 218398919 - 2¹⁶ = 218333383 is a prime.

It is a super-2 number, since 2×218398919² = 95396175640737122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (218398909) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 52799 + ... + 56784.

It is an arithmetic number, because the mean of its divisors is an integer number (54627624).

Almost surely, 2^218398919 is an apocalyptic number.

218398919 is a deficient number, since it is larger than the sum of its proper divisors (111577).

218398919 is a wasteful number, since it uses less digits than its factorization.

218398919 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 111576.

The product of its digits is 279936, while the sum is 50.

The square root of 218398919 is about 14778.3259877430. The cubic root of 218398919 is about 602.2130486202.

The spelling of 218398919 in words is "two hundred eighteen million, three hundred ninety-eight thousand, nine hundred nineteen".