21421454 has 8 divisors (see below), whose sum is σ = 32182920. Its totient is φ = 10693816.

The previous prime is 21421453. The next prime is 21421489. The reversal of 21421454 is 45412412.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21421451) 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, 6809 + ... + 9444.

It is an arithmetic number, because the mean of its divisors is an integer number (4022865).

Almost surely, 2^21421454 is an apocalyptic number.

21421454 is a deficient number, since it is larger than the sum of its proper divisors (10761466).

21421454 is a wasteful number, since it uses less digits than its factorization.

21421454 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16914.

The product of its digits is 1280, while the sum is 23.

The square root of 21421454 is about 4628.3316648659. The cubic root of 21421454 is about 277.7258567609.

Adding to 21421454 its reverse (45412412), we get a palindrome (66833866).

The spelling of 21421454 in words is "twenty-one million, four hundred twenty-one thousand, four hundred fifty-four".