218320638 has 16 divisors (see below), whose sum is σ = 437218320. Its totient is φ = 72677376.

The previous prime is 218320607. The next prime is 218320651. The reversal of 218320638 is 836023812.

It is a junction number, because it is equal to n+sod(n) for n = 218320599 and 218320608.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19045 + ... + 28272.

It is an arithmetic number, because the mean of its divisors is an integer number (27326145).

Almost surely, 2^218320638 is an apocalyptic number.

218320638 is an abundant number, since it is smaller than the sum of its proper divisors (218897682).

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

218320638 is a wasteful number, since it uses less digits than its factorization.

218320638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48091.

The product of its (nonzero) digits is 13824, while the sum is 33.

The square root of 218320638 is about 14775.6772433618. The cubic root of 218320638 is about 602.1410893612.

The spelling of 218320638 in words is "two hundred eighteen million, three hundred twenty thousand, six hundred thirty-eight".