21056122 has 4 divisors (see below), whose sum is σ = 31584186. Its totient is φ = 10528060.

The previous prime is 21056089. The next prime is 21056129. The reversal of 21056122 is 22165012.

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

It can be written as a sum of positive squares in only one way, i.e., 13771521 + 7284601 = 3711^2 + 2699^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21056122.

It is not an unprimeable number, because it can be changed into a prime (21056129) by changing a digit.

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, 5264029 + ... + 5264032.

Almost surely, 2^21056122 is an apocalyptic number.

21056122 is a deficient number, since it is larger than the sum of its proper divisors (10528064).

21056122 is a wasteful number, since it uses less digits than its factorization.

21056122 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10528063.

The product of its (nonzero) digits is 240, while the sum is 19.

The square root of 21056122 is about 4588.6950214631. The cubic root of 21056122 is about 276.1379709951.

The spelling of 21056122 in words is "twenty-one million, fifty-six thousand, one hundred twenty-two".