21446340 has 48 divisors (see below), whose sum is σ = 60661440. Its totient is φ = 5660800.

The previous prime is 21446339. The next prime is 21446371. The reversal of 21446340 is 4364412.

It is a self number, because there is not a number n which added to its sum of digits gives 21446340.

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 15 ways as a sum of consecutive naturals, for example, 4291 + ... + 7829.

It is an arithmetic number, because the mean of its divisors is an integer number (1263780).

Almost surely, 2^21446340 is an apocalyptic number.

21446340 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 21446340, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30330720).

21446340 is an abundant number, since it is smaller than the sum of its proper divisors (39215100).

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

21446340 is a wasteful number, since it uses less digits than its factorization.

21446340 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3652 (or 3650 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 24.

The square root of 21446340 is about 4631.0193262391. The cubic root of 21446340 is about 277.8333628615.

The spelling of 21446340 in words is "twenty-one million, four hundred forty-six thousand, three hundred forty".