21053122 has 4 divisors (see below), whose sum is σ = 31579686. Its totient is φ = 10526560.

The previous prime is 21053117. The next prime is 21053129. The reversal of 21053122 is 22135012.

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., 10883401 + 10169721 = 3299^2 + 3189^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21053096 and 21053105.

It is not an unprimeable number, because it can be changed into a prime (21053129) 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, 5263279 + ... + 5263282.

Almost surely, 2^21053122 is an apocalyptic number.

21053122 is a deficient number, since it is larger than the sum of its proper divisors (10526564).

21053122 is a wasteful number, since it uses less digits than its factorization.

21053122 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10526563.

The product of its (nonzero) digits is 120, while the sum is 16.

The square root of 21053122 is about 4588.3681194952. The cubic root of 21053122 is about 276.1248559929.

Adding to 21053122 its reverse (22135012), we get a palindrome (43188134).

The spelling of 21053122 in words is "twenty-one million, fifty-three thousand, one hundred twenty-two".