21204011 has 8 divisors (see below), whose sum is σ = 21787584. Its totient is φ = 20623680.

The previous prime is 21203977. The next prime is 21204013. The reversal of 21204011 is 11040212.

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-21204011 is a prime.

It is a super-2 number, since 2×21204011² = 899220164976242, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21203983 and 21204001.

It is not an unprimeable number, because it can be changed into a prime (21204013) 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 7 ways as a sum of consecutive naturals, for example, 18425 + ... + 19541.

It is an arithmetic number, because the mean of its divisors is an integer number (2723448).

Almost surely, 2^21204011 is an apocalyptic number.

21204011 is a deficient number, since it is larger than the sum of its proper divisors (583573).

21204011 is a wasteful number, since it uses less digits than its factorization.

21204011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1621.

The product of its (nonzero) digits is 16, while the sum is 11.

The square root of 21204011 is about 4604.7813194548. The cubic root of 21204011 is about 276.7829541317.

Adding to 21204011 its reverse (11040212), we get a palindrome (32244223).

The spelling of 21204011 in words is "twenty-one million, two hundred four thousand, eleven".