218400725 has 12 divisors (see below), whose sum is σ = 285071040. Its totient is φ = 165524400.

The previous prime is 218400719. The next prime is 218400731. The reversal of 218400725 is 527004812.

It is an interprime number because it is at equal distance from previous prime (218400719) and next prime (218400731).

It is not a de Polignac number, because 218400725 - 2¹⁸ = 218138581 is a prime.

It is a congruent number.

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, 229421 + ... + 230370.

It is an arithmetic number, because the mean of its divisors is an integer number (23755920).

Almost surely, 2^218400725 is an apocalyptic number.

218400725 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

218400725 is a deficient number, since it is larger than the sum of its proper divisors (66670315).

218400725 is a wasteful number, since it uses less digits than its factorization.

218400725 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 459820 (or 459815 counting only the distinct ones).

The product of its (nonzero) digits is 4480, while the sum is 29.

The square root of 218400725 is about 14778.3870906131. The cubic root of 218400725 is about 602.2147085701.

The spelling of 218400725 in words is "two hundred eighteen million, four hundred thousand, seven hundred twenty-five".