218540478 has 16 divisors (see below), whose sum is σ = 470702736. Its totient is φ = 67243200.

The previous prime is 218540477. The next prime is 218540519. The reversal of 218540478 is 874045812.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (218540471) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1400823 + ... + 1400978.

It is an arithmetic number, because the mean of its divisors is an integer number (29418921).

Almost surely, 2^218540478 is an apocalyptic number.

218540478 is an abundant number, since it is smaller than the sum of its proper divisors (252162258).

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

218540478 is a wasteful number, since it uses less digits than its factorization.

218540478 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2801819.

The product of its (nonzero) digits is 71680, while the sum is 39.

The square root of 218540478 is about 14783.1146244626. The cubic root of 218540478 is about 602.3431320863.

The spelling of 218540478 in words is "two hundred eighteen million, five hundred forty thousand, four hundred seventy-eight".