21553126 has 16 divisors (see below), whose sum is σ = 37850400. Its totient is φ = 9011520.

The previous prime is 21553123. The next prime is 21553141. The reversal of 21553126 is 62135512.

It is a self number, because there is not a number n which added to its sum of digits gives 21553126.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21553123) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18201 + ... + 19348.

It is an arithmetic number, because the mean of its divisors is an integer number (2365650).

Almost surely, 2^21553126 is an apocalyptic number.

21553126 is a deficient number, since it is larger than the sum of its proper divisors (16297274).

21553126 is a wasteful number, since it uses less digits than its factorization.

21553126 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37599.

The product of its digits is 1800, while the sum is 25.

The square root of 21553126 is about 4642.5344371367. The cubic root of 21553126 is about 278.2937305656.

Adding to 21553126 its reverse (62135512), we get a palindrome (83688638).

The spelling of 21553126 in words is "twenty-one million, five hundred fifty-three thousand, one hundred twenty-six".