21221011 has 8 divisors (see below), whose sum is σ = 25089120. Its totient is φ = 17562048.

The previous prime is 21221003. The next prime is 21221021. The reversal of 21221011 is 11012212.

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

It is not a de Polignac number, because 21221011 - 2³ = 21221003 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21221021) 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, 52066 + ... + 52471.

It is an arithmetic number, because the mean of its divisors is an integer number (3136140).

Almost surely, 2^21221011 is an apocalyptic number.

21221011 is a deficient number, since it is larger than the sum of its proper divisors (3868109).

21221011 is a wasteful number, since it uses less digits than its factorization.

21221011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 104573.

The product of its (nonzero) digits is 8, while the sum is 10.

The square root of 21221011 is about 4606.6268570398. The cubic root of 21221011 is about 276.8569032430.

Adding to 21221011 its reverse (11012212), we get a palindrome (32233223).

The spelling of 21221011 in words is "twenty-one million, two hundred twenty-one thousand, eleven".