21459481 has 4 divisors (see below), whose sum is σ = 21731200. Its totient is φ = 21187764.

The previous prime is 21459479. The next prime is 21459499. The reversal of 21459481 is 18495412.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21459481 - 2¹ = 21459479 is a prime.

It is a super-2 number, since 2×21459481² = 921018649578722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21459181) 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, 135741 + ... + 135898.

It is an arithmetic number, because the mean of its divisors is an integer number (5432800).

Almost surely, 2^21459481 is an apocalyptic number.

It is an amenable number.

21459481 is a deficient number, since it is larger than the sum of its proper divisors (271719).

21459481 is an equidigital number, since it uses as much as digits as its factorization.

21459481 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 271718.

The product of its digits is 11520, while the sum is 34.

The square root of 21459481 is about 4632.4379110788. The cubic root of 21459481 is about 277.8900976823.

It can be divided in two parts, 214 and 59481, that added together give a palindrome (59695).

The spelling of 21459481 in words is "twenty-one million, four hundred fifty-nine thousand, four hundred eighty-one".