21111030 has 80 divisors (see below), whose sum is σ = 57760560. Its totient is φ = 5531328.

The previous prime is 21111029. The next prime is 21111049. The reversal of 21111030 is 3011112.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 54076 + ... + 54464.

It is an arithmetic number, because the mean of its divisors is an integer number (722007).

Almost surely, 2^21111030 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21111030, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28880280).

21111030 is an abundant number, since it is smaller than the sum of its proper divisors (36649530).

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

21111030 is a wasteful number, since it uses less digits than its factorization.

21111030 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 475 (or 466 counting only the distinct ones).

The product of its (nonzero) digits is 6, while the sum is 9.

The square root of 21111030 is about 4594.6740907272. The cubic root of 21111030 is about 276.3777907699.

Adding to 21111030 its reverse (3011112), we get a palindrome (24122142).

The spelling of 21111030 in words is "twenty-one million, one hundred eleven thousand, thirty".