21211038 has 32 divisors (see below), whose sum is σ = 47589120. Its totient is φ = 7002360.

The previous prime is 21211033. The next prime is 21211039. The reversal of 21211038 is 83011212.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a self number, because there is not a number n which added to its sum of digits gives 21211038.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21211033) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3943 + ... + 7613.

It is an arithmetic number, because the mean of its divisors is an integer number (1487160).

Almost surely, 2^21211038 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21211038, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23794560).

21211038 is an abundant number, since it is smaller than the sum of its proper divisors (26378082).

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

21211038 is a wasteful number, since it uses less digits than its factorization.

21211038 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3789 (or 3783 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 18.

The square root of 21211038 is about 4605.5442675106. The cubic root of 21211038 is about 276.8135260049.

The spelling of 21211038 in words is "twenty-one million, two hundred eleven thousand, thirty-eight".