21618834 has 16 divisors (see below), whose sum is σ = 43292640. Its totient is φ = 7197120.

The previous prime is 21618803. The next prime is 21618847. The reversal of 21618834 is 43881612.

It is a junction number, because it is equal to n+sod(n) for n = 21618795 and 21618804.

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, 4269 + ... + 7839.

It is an arithmetic number, because the mean of its divisors is an integer number (2705790).

Almost surely, 2^21618834 is an apocalyptic number.

21618834 is an abundant number, since it is smaller than the sum of its proper divisors (21673806).

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

21618834 is a wasteful number, since it uses less digits than its factorization.

21618834 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4585.

The product of its digits is 9216, while the sum is 33.

The square root of 21618834 is about 4649.6057897417. The cubic root of 21618834 is about 278.5762506538.

The spelling of 21618834 in words is "twenty-one million, six hundred eighteen thousand, eight hundred thirty-four".