21654402 has 48 divisors (see below), whose sum is σ = 54417216. Its totient is φ = 5623200.

The previous prime is 21654383. The next prime is 21654419. The reversal of 21654402 is 20445612.

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 2952 + ... + 7212.

It is an arithmetic number, because the mean of its divisors is an integer number (1133692).

Almost surely, 2^21654402 is an apocalyptic number.

21654402 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 21654402, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27208608).

21654402 is an abundant number, since it is smaller than the sum of its proper divisors (32762814).

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

21654402 is a wasteful number, since it uses less digits than its factorization.

21654402 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4295 (or 4284 counting only the distinct ones).

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

The square root of 21654402 is about 4653.4290582322. The cubic root of 21654402 is about 278.7289411454.

The spelling of 21654402 in words is "twenty-one million, six hundred fifty-four thousand, four hundred two".