218342440 has 32 divisors (see below), whose sum is σ = 492300000. Its totient is φ = 87153984.

The previous prime is 218342437. The next prime is 218342459. The reversal of 218342440 is 44243812.

It is a happy number.

It is a super-2 number, since 2×218342440² = 95346842210307200, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 218342399 and 218342408.

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, 14491 + ... + 25429.

It is an arithmetic number, because the mean of its divisors is an integer number (15384375).

Almost surely, 2^218342440 is an apocalyptic number.

218342440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

218342440 is an abundant number, since it is smaller than the sum of its proper divisors (273957560).

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

218342440 is a wasteful number, since it uses less digits than its factorization.

218342440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11449 (or 11445 counting only the distinct ones).

The product of its (nonzero) digits is 6144, while the sum is 28.

The square root of 218342440 is about 14776.4149914653. The cubic root of 218342440 is about 602.1611324244.

The spelling of 218342440 in words is "two hundred eighteen million, three hundred forty-two thousand, four hundred forty".