21654396 has 72 divisors (see below), whose sum is σ = 59439744. Its totient is φ = 6620160.

The previous prime is 21654383. The next prime is 21654419. The reversal of 21654396 is 69345612.

It is a happy number.

21654396 is a `hidden beast` number, since 21 + 6 + 543 + 96 = 666.

It is a super-2 number, since 2×21654396² = 937825732249632, which contains 22 as substring.

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

It is a self number, because there is not a number n which added to its sum of digits gives 21654396.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 24661 + ... + 25523.

It is an arithmetic number, because the mean of its divisors is an integer number (825552).

Almost surely, 2^21654396 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 21654396, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29719872).

21654396 is an abundant number, since it is smaller than the sum of its proper divisors (37785348).

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

21654396 is a wasteful number, since it uses less digits than its factorization.

21654396 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 931 (or 926 counting only the distinct ones).

The product of its digits is 38880, while the sum is 36.

The square root of 21654396 is about 4653.4284135463. The cubic root of 21654396 is about 278.7289154020.

It can be divided in two parts, 2165 and 4396, that added together give a 8-th power (6561 = 3⁸).

The spelling of 21654396 in words is "twenty-one million, six hundred fifty-four thousand, three hundred ninety-six".