21212773 has 8 divisors (see below), whose sum is σ = 22311936. Its totient is φ = 20139600.

The previous prime is 21212749. The next prime is 21212777. The reversal of 21212773 is 37721212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21212773 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21212777) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 4813 + ... + 8098.

It is an arithmetic number, because the mean of its divisors is an integer number (2788992).

Almost surely, 2^21212773 is an apocalyptic number.

It is an amenable number.

21212773 is a deficient number, since it is larger than the sum of its proper divisors (1099163).

21212773 is a wasteful number, since it uses less digits than its factorization.

21212773 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12995.

The product of its digits is 1176, while the sum is 25.

The square root of 21212773 is about 4605.7326235899. The cubic root of 21212773 is about 276.8210733076.

Adding to 21212773 its reverse (37721212), we get a palindrome (58933985).

The spelling of 21212773 in words is "twenty-one million, two hundred twelve thousand, seven hundred seventy-three".