21211004 has 24 divisors (see below), whose sum is σ = 37806048. Its totient is φ = 10411520.

The previous prime is 21210989. The next prime is 21211009. The reversal of 21211004 is 40011212.

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 polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 75344 + ... + 75624.

It is an arithmetic number, because the mean of its divisors is an integer number (1575252).

Almost surely, 2^21211004 is an apocalyptic number.

It is an amenable number.

21211004 is a deficient number, since it is larger than the sum of its proper divisors (16595044).

21211004 is a wasteful number, since it uses less digits than its factorization.

21211004 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 565 (or 563 counting only the distinct ones).

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

The square root of 21211004 is about 4605.5405763059. The cubic root of 21211004 is about 276.8133780998.

Adding to 21211004 its reverse (40011212), we get a palindrome (61222216).

It can be divided in two parts, 2121 and 1004, that added together give a 5-th power (3125 = 5⁵).

The spelling of 21211004 in words is "twenty-one million, two hundred eleven thousand, four".