21320120 has 16 divisors (see below), whose sum is σ = 47970360. Its totient is φ = 8528032.

The previous prime is 21320107. The next prime is 21320183. The reversal of 21320120 is 2102312.

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 (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 266462 + ... + 266541.

Almost surely, 2^21320120 is an apocalyptic number.

21320120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21320120 is an abundant number, since it is smaller than the sum of its proper divisors (26650240).

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

21320120 is a wasteful number, since it uses less digits than its factorization.

21320120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 533014 (or 533010 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 11.

The square root of 21320120 is about 4617.3715466702. The cubic root of 21320120 is about 277.2872378291.

Adding to 21320120 its reverse (2102312), we get a palindrome (23422432).

The spelling of 21320120 in words is "twenty-one million, three hundred twenty thousand, one hundred twenty".