21434481 has 6 divisors (see below), whose sum is σ = 30960930. Its totient is φ = 14289648.

The previous prime is 21434471. The next prime is 21434531. The reversal of 21434481 is 18443412.

21434481 is a `hidden beast` number, since 214 + 3 + 448 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 19000881 + 2433600 = 4359^2 + 1560^2 .

It is not a de Polignac number, because 21434481 - 2⁵ = 21434449 is a prime.

It is a super-2 number, since 2×21434481² = 918873951478722, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21434401) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1190796 + ... + 1190813.

It is an arithmetic number, because the mean of its divisors is an integer number (5160155).

Almost surely, 2^21434481 is an apocalyptic number.

It is an amenable number.

21434481 is a deficient number, since it is larger than the sum of its proper divisors (9526449).

21434481 is a wasteful number, since it uses less digits than its factorization.

21434481 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2381615 (or 2381612 counting only the distinct ones).

The product of its digits is 3072, while the sum is 27.

The square root of 21434481 is about 4629.7387615286. The cubic root of 21434481 is about 277.7821430366.

Adding to 21434481 its reverse (18443412), we get a palindrome (39877893).

The spelling of 21434481 in words is "twenty-one million, four hundred thirty-four thousand, four hundred eighty-one".