218694121 has 4 divisors (see below), whose sum is σ = 220267600. Its totient is φ = 217120644.

The previous prime is 218694101. The next prime is 218694131. The reversal of 218694121 is 121496812.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-218694121 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (218694101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 786531 + ... + 786808.

It is an arithmetic number, because the mean of its divisors is an integer number (55066900).

Almost surely, 2^218694121 is an apocalyptic number.

It is an amenable number.

218694121 is a deficient number, since it is larger than the sum of its proper divisors (1573479).

218694121 is a wasteful number, since it uses less digits than its factorization.

218694121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1573478.

The product of its digits is 6912, while the sum is 34.

The square root of 218694121 is about 14788.3102821113. The cubic root of 218694121 is about 602.4842564024.

The spelling of 218694121 in words is "two hundred eighteen million, six hundred ninety-four thousand, one hundred twenty-one".