21404526 has 96 divisors (see below), whose sum is σ = 53758080. Its totient is φ = 5616000.

The previous prime is 21404503. The next prime is 21404531. The reversal of 21404526 is 62540412.

It is a junction number, because it is equal to n+sod(n) for n = 21404496 and 21404505.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 211876 + ... + 211976.

It is an arithmetic number, because the mean of its divisors is an integer number (559980).

Almost surely, 2^21404526 is an apocalyptic number.

21404526 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 21404526, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26879040).

21404526 is an abundant number, since it is smaller than the sum of its proper divisors (32353554).

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

21404526 is a wasteful number, since it uses less digits than its factorization.

21404526 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 162 (or 149 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 24.

The square root of 21404526 is about 4626.5025667344. The cubic root of 21404526 is about 277.6526811767.

Adding to 21404526 its reverse (62540412), we get a palindrome (83944938).

It can be divided in two parts, 2140 and 4526, that added together give a palindrome (6666).

The spelling of 21404526 in words is "twenty-one million, four hundred four thousand, five hundred twenty-six".