21075844 has 12 divisors (see below), whose sum is σ = 36927324. Its totient is φ = 10525184.

The previous prime is 21075839. The next prime is 21075851. The reversal of 21075844 is 44857012.

It can be written as a sum of positive squares in 2 ways, for example, as 19909444 + 1166400 = 4462^2 + 1080^2 .

It is a super-3 number, since 3×21075844³ (a number of 23 digits) contains 333 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1212 + ... + 6604.

It is an arithmetic number, because the mean of its divisors is an integer number (3077277).

Almost surely, 2^21075844 is an apocalyptic number.

It is an amenable number.

21075844 is a deficient number, since it is larger than the sum of its proper divisors (15851480).

21075844 is a wasteful number, since it uses less digits than its factorization.

21075844 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6374 (or 6372 counting only the distinct ones).

The product of its (nonzero) digits is 8960, while the sum is 31.

The square root of 21075844 is about 4590.8434954810. The cubic root of 21075844 is about 276.2241580216.

The spelling of 21075844 in words is "twenty-one million, seventy-five thousand, eight hundred forty-four".