218661442 has 4 divisors (see below), whose sum is σ = 327992166. Its totient is φ = 109330720.

The previous prime is 218661433. The next prime is 218661451. The reversal of 218661442 is 244166812.

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

It is an interprime number because it is at equal distance from previous prime (218661433) and next prime (218661451).

It can be written as a sum of positive squares in only one way, i.e., 138039001 + 80622441 = 11749^2 + 8979^2 .

It is a junction number, because it is equal to n+sod(n) for n = 218661398 and 218661407.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 54665359 + ... + 54665362.

Almost surely, 2^218661442 is an apocalyptic number.

218661442 is a deficient number, since it is larger than the sum of its proper divisors (109330724).

218661442 is a wasteful number, since it uses less digits than its factorization.

218661442 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 109330723.

The product of its digits is 18432, while the sum is 34.

The square root of 218661442 is about 14787.2053478675. The cubic root of 218661442 is about 602.4542455914.

The spelling of 218661442 in words is "two hundred eighteen million, six hundred sixty-one thousand, four hundred forty-two".