21344620 has 24 divisors (see below), whose sum is σ = 48899088. Its totient is φ = 7761600.

The previous prime is 21344593. The next prime is 21344623. The reversal of 21344620 is 2644312.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is a junction number, because it is equal to n+sod(n) for n = 21344591 and 21344600.

It is not an unprimeable number, because it can be changed into a prime (21344623) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 48291 + ... + 48730.

It is an arithmetic number, because the mean of its divisors is an integer number (2037462).

Almost surely, 2^21344620 is an apocalyptic number.

21344620 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21344620 is an abundant number, since it is smaller than the sum of its proper divisors (27554468).

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

21344620 is a wasteful number, since it uses less digits than its factorization.

21344620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 97041 (or 97039 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 22.

The square root of 21344620 is about 4620.0238094625. The cubic root of 21344620 is about 277.3934119770.

Adding to 21344620 its reverse (2644312), we get a palindrome (23988932).

The spelling of 21344620 in words is "twenty-one million, three hundred forty-four thousand, six hundred twenty".