21481163 has 4 divisors (see below), whose sum is σ = 23434008. Its totient is φ = 19528320.

The previous prime is 21481111. The next prime is 21481177. The reversal of 21481163 is 36118412.

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 21481163 - 2¹⁶ = 21415627 is a prime.

It is a super-2 number, since 2×21481163² = 922880727665138, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21481193) 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, 976406 + ... + 976427.

It is an arithmetic number, because the mean of its divisors is an integer number (5858502).

Almost surely, 2^21481163 is an apocalyptic number.

21481163 is a deficient number, since it is larger than the sum of its proper divisors (1952845).

21481163 is a wasteful number, since it uses less digits than its factorization.

21481163 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1952844.

The product of its digits is 1152, while the sum is 26.

The square root of 21481163 is about 4634.7775566903. Note that the first 3 decimals coincide. The cubic root of 21481163 is about 277.9836567174.

Adding to 21481163 its reverse (36118412), we get a palindrome (57599575).

It can be divided in two parts, 21 and 481163, that added together give a palindrome (481184).

The spelling of 21481163 in words is "twenty-one million, four hundred eighty-one thousand, one hundred sixty-three".