21321060 has 48 divisors (see below), whose sum is σ = 63213696. Its totient is φ = 5350912.

The previous prime is 21321031. The next prime is 21321067. The reversal of 21321060 is 6012312.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21321067) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 9432 + ... + 11471.

It is an arithmetic number, because the mean of its divisors is an integer number (1316952).

Almost surely, 2^21321060 is an apocalyptic number.

21321060 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21321060 is an abundant number, since it is smaller than the sum of its proper divisors (41892636).

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

21321060 is a wasteful number, since it uses less digits than its factorization.

21321060 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20932 (or 20930 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 15.

The square root of 21321060 is about 4617.4733350611. The cubic root of 21321060 is about 277.2913129496.

Adding to 21321060 its reverse (6012312), we get a palindrome (27333372).

The spelling of 21321060 in words is "twenty-one million, three hundred twenty-one thousand, sixty".