21075836 has 6 divisors (see below), whose sum is σ = 36882720. Its totient is φ = 10537916.

The previous prime is 21075833. The next prime is 21075839. The reversal of 21075836 is 63857012.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21075833) and next prime (21075839).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21075833) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2634476 + ... + 2634483.

It is an arithmetic number, because the mean of its divisors is an integer number (6147120).

Almost surely, 2^21075836 is an apocalyptic number.

It is an amenable number.

21075836 is a deficient number, since it is larger than the sum of its proper divisors (15806884).

21075836 is a wasteful number, since it uses less digits than its factorization.

21075836 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5268963 (or 5268961 counting only the distinct ones).

The product of its (nonzero) digits is 10080, while the sum is 32.

The square root of 21075836 is about 4590.8426241813. The cubic root of 21075836 is about 276.2241230718.

The spelling of 21075836 in words is "twenty-one million, seventy-five thousand, eight hundred thirty-six".