218764921 has 8 divisors (see below), whose sum is σ = 220387104. Its totient is φ = 217148160.

The previous prime is 218764919. The next prime is 218764957. The reversal of 218764921 is 129467812.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 218764921 - 2¹ = 218764919 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (218764961) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 112326 + ... + 114256.

It is an arithmetic number, because the mean of its divisors is an integer number (27548388).

Almost surely, 2^218764921 is an apocalyptic number.

It is an amenable number.

218764921 is a deficient number, since it is larger than the sum of its proper divisors (1622183).

218764921 is a wasteful number, since it uses less digits than its factorization.

218764921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2711.

The product of its digits is 48384, while the sum is 40.

The square root of 218764921 is about 14790.7038710130. The cubic root of 218764921 is about 602.5492654400.

The spelling of 218764921 in words is "two hundred eighteen million, seven hundred sixty-four thousand, nine hundred twenty-one".