21211000 has 32 divisors (see below), whose sum is σ = 49636080. Its totient is φ = 8484000.

The previous prime is 21210989. The next prime is 21211009. The reversal of 21211000 is 11212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21211009) 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, 9606 + ... + 11605.

Almost surely, 2^21211000 is an apocalyptic number.

21211000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21211000 is an abundant number, since it is smaller than the sum of its proper divisors (28425080).

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

21211000 is a wasteful number, since it uses less digits than its factorization.

21211000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21232 (or 21218 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 7.

The square root of 21211000 is about 4605.5401420463. The cubic root of 21211000 is about 276.8133606992.

Adding to 21211000 its reverse (11212), we get a palindrome (21222212).

The spelling of 21211000 in words is "twenty-one million, two hundred eleven thousand".