213618816 has 128 divisors (see below), whose sum is σ = 637214400. Its totient is φ = 70447104.

The previous prime is 213618809. The next prime is 213618817. The reversal of 213618816 is 618816312.

213618816 is a `hidden beast` number, since 21 + 3 + 618 + 8 + 16 = 666.

It is a tau number, because it is divible by the number of its divisors (128).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (213618817) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 390255 + ... + 390801.

Almost surely, 2^213618816 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 213618816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (318607200).

213618816 is an abundant number, since it is smaller than the sum of its proper divisors (423595584).

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

213618816 is a wasteful number, since it uses less digits than its factorization.

213618816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 683 (or 665 counting only the distinct ones).

The product of its digits is 13824, while the sum is 36.

The square root of 213618816 is about 14615.7044305090. The cubic root of 213618816 is about 597.7870481076.

The spelling of 213618816 in words is "two hundred thirteen million, six hundred eighteen thousand, eight hundred sixteen".