21553411 has 4 divisors (see below), whose sum is σ = 23512824. Its totient is φ = 19594000.

The previous prime is 21553403. The next prime is 21553417. The reversal of 21553411 is 11435512.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 21553411 - 2³ = 21553403 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21553417) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 979690 + ... + 979711.

It is an arithmetic number, because the mean of its divisors is an integer number (5878206).

Almost surely, 2^21553411 is an apocalyptic number.

21553411 is a deficient number, since it is larger than the sum of its proper divisors (1959413).

21553411 is a wasteful number, since it uses less digits than its factorization.

21553411 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1959412.

The product of its digits is 600, while the sum is 22.

The square root of 21553411 is about 4642.5651314763. The cubic root of 21553411 is about 278.2949571992.

Adding to 21553411 its reverse (11435512), we get a palindrome (32988923).

The spelling of 21553411 in words is "twenty-one million, five hundred fifty-three thousand, four hundred eleven".