218445642 has 24 divisors (see below), whose sum is σ = 475920900. Its totient is φ = 72411840.

The previous prime is 218445637. The next prime is 218445653. The reversal of 218445642 is 246544812.

218445642 is a `hidden beast` number, since 2 + 1 + 8 + 4 + 4 + 5 + 642 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 184117761 + 34327881 = 13569^2 + 5859^2 .

It is a junction number, because it is equal to n+sod(n) for n = 218445597 and 218445606.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 30267 + ... + 36782.

Almost surely, 2^218445642 is an apocalyptic number.

218445642 is an abundant number, since it is smaller than the sum of its proper divisors (257475258).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

218445642 is a wasteful number, since it uses less digits than its factorization.

218445642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 67238 (or 67235 counting only the distinct ones).

The product of its digits is 61440, while the sum is 36.

The square root of 218445642 is about 14779.9066979464. The cubic root of 218445642 is about 602.2559902156.

The spelling of 218445642 in words is "two hundred eighteen million, four hundred forty-five thousand, six hundred forty-two".