21179481 has 8 divisors (see below), whose sum is σ = 29467200. Its totient is φ = 13505712.

The previous prime is 21179453. The next prime is 21179491. The reversal of 21179481 is 18497112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21179481 - 2⁵ = 21179449 is a prime.

It is a super-2 number, since 2×21179481² = 897140830858722, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21179401) 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 in 7 ways as a sum of consecutive naturals, for example, 153406 + ... + 153543.

It is an arithmetic number, because the mean of its divisors is an integer number (3683400).

Almost surely, 2^21179481 is an apocalyptic number.

It is an amenable number.

21179481 is a deficient number, since it is larger than the sum of its proper divisors (8287719).

21179481 is a wasteful number, since it uses less digits than its factorization.

21179481 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 306975.

The product of its digits is 4032, while the sum is 33.

The square root of 21179481 is about 4602.1170128540. The cubic root of 21179481 is about 276.6761802183.

The spelling of 21179481 in words is "twenty-one million, one hundred seventy-nine thousand, four hundred eighty-one".