21018096 has 80 divisors (see below), whose sum is σ = 65829120. Its totient is φ = 6367680.

The previous prime is 21018091. The next prime is 21018097. The reversal of 21018096 is 69081012.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21018091) 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, 2541 + ... + 6963.

It is an arithmetic number, because the mean of its divisors is an integer number (822864).

Almost surely, 2^21018096 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 21018096, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32914560).

21018096 is an abundant number, since it is smaller than the sum of its proper divisors (44811024).

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

21018096 is a wasteful number, since it uses less digits than its factorization.

21018096 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4451 (or 4439 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 27.

The square root of 21018096 is about 4584.5497052600. The cubic root of 21018096 is about 275.9716416988.

It can be divided in two parts, 210180 and 96, that added together give a triangular number (210276 = T₆₄₈).

The spelling of 21018096 in words is "twenty-one million, eighteen thousand, ninety-six".