21236754 has 64 divisors (see below), whose sum is σ = 54236160. Its totient is φ = 5382720.

The previous prime is 21236753. The next prime is 21236771. The reversal of 21236754 is 45763212.

It is a super-3 number, since 3×21236754³ (a number of 23 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (21236753) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 19332 + ... + 20400.

It is an arithmetic number, because the mean of its divisors is an integer number (847440).

Almost surely, 2^21236754 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21236754, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27118080).

21236754 is an abundant number, since it is smaller than the sum of its proper divisors (32999406).

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

21236754 is a wasteful number, since it uses less digits than its factorization.

21236754 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1135.

The product of its digits is 10080, while the sum is 30.

The square root of 21236754 is about 4608.3352742612. The cubic root of 21236754 is about 276.9253492572.

Adding to 21236754 its reverse (45763212), we get a palindrome (66999966).

The spelling of 21236754 in words is "twenty-one million, two hundred thirty-six thousand, seven hundred fifty-four".