21226860 has 60 divisors (see below), whose sum is σ = 66594528. Its totient is φ = 5660064.

The previous prime is 21226853. The next prime is 21226879. The reversal of 21226860 is 6862212.

It is a tau number, because it is divible by the number of its divisors (60).

It is a Harshad number since it is a multiple of its sum of digits (27).

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 19 ways as a sum of consecutive naturals, for example, 4932 + ... + 8171.

Almost surely, 2^21226860 is an apocalyptic number.

21226860 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21226860 is an abundant number, since it is smaller than the sum of its proper divisors (45367668).

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

21226860 is a wasteful number, since it uses less digits than its factorization.

21226860 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13124 (or 13113 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 27.

The square root of 21226860 is about 4607.2616595978. The cubic root of 21226860 is about 276.8823369555.

It can be divided in two parts, 212 and 26860, that added together give a palindrome (27072).

The spelling of 21226860 in words is "twenty-one million, two hundred twenty-six thousand, eight hundred sixty".