21034511 has 4 divisors (see below), whose sum is σ = 21046152. Its totient is φ = 21022872.

The previous prime is 21034471. The next prime is 21034513. The reversal of 21034511 is 11543012.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21034511 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21034511.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21034513) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2465 + ... + 6938.

It is an arithmetic number, because the mean of its divisors is an integer number (5261538).

Almost surely, 2^21034511 is an apocalyptic number.

21034511 is a deficient number, since it is larger than the sum of its proper divisors (11641).

21034511 is an equidigital number, since it uses as much as digits as its factorization.

21034511 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11640.

The product of its (nonzero) digits is 120, while the sum is 17.

The square root of 21034511 is about 4586.3396080099. The cubic root of 21034511 is about 276.0434670391.

Adding to 21034511 its reverse (11543012), we get a palindrome (32577523).

The spelling of 21034511 in words is "twenty-one million, thirty-four thousand, five hundred eleven".