21042526 has 4 divisors (see below), whose sum is σ = 31563792. Its totient is φ = 10521262.

The previous prime is 21042491. The next prime is 21042533. The reversal of 21042526 is 62524012.

It is a semiprime because it is the product of two primes.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a junction number, because it is equal to n+sod(n) for n = 21042497 and 21042506.

It is a congruent number.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 5260630 + ... + 5260633.

It is an arithmetic number, because the mean of its divisors is an integer number (7890948).

Almost surely, 2^21042526 is an apocalyptic number.

21042526 is a deficient number, since it is larger than the sum of its proper divisors (10521266).

21042526 is a wasteful number, since it uses less digits than its factorization.

21042526 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10521265.

The product of its (nonzero) digits is 960, while the sum is 22.

The square root of 21042526 is about 4587.2133152928. The cubic root of 21042526 is about 276.0785238311.

Adding to 21042526 its reverse (62524012), we get a palindrome (83566538).

The spelling of 21042526 in words is "twenty-one million, forty-two thousand, five hundred twenty-six".