21343860 has 72 divisors (see below), whose sum is σ = 65126880. Its totient is φ = 5658048.

The previous prime is 21343853. The next prime is 21343901. The reversal of 21343860 is 6834312.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 50731 + ... + 51149.

It is an arithmetic number, because the mean of its divisors is an integer number (904540).

Almost surely, 2^21343860 is an apocalyptic number.

21343860 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21343860, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32563440).

21343860 is an abundant number, since it is smaller than the sum of its proper divisors (43783020).

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

21343860 is a wasteful number, since it uses less digits than its factorization.

21343860 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 717 (or 712 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 27.

The square root of 21343860 is about 4619.9415580719. The cubic root of 21343860 is about 277.3901196330.

The spelling of 21343860 in words is "twenty-one million, three hundred forty-three thousand, eight hundred sixty".