21462421 has 4 divisors (see below), whose sum is σ = 21531744. Its totient is φ = 21393100.

The previous prime is 21462401. The next prime is 21462433. The reversal of 21462421 is 12426412.

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 21462421 - 2⁷ = 21462293 is a prime.

It is a super-3 number, since 3×21462421³ (a number of 23 digits) contains 333 as substring.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21462392 and 21462401.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21462401) 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, 34195 + ... + 34816.

It is an arithmetic number, because the mean of its divisors is an integer number (5382936).

Almost surely, 2^21462421 is an apocalyptic number.

It is an amenable number.

21462421 is a deficient number, since it is larger than the sum of its proper divisors (69323).

21462421 is an equidigital number, since it uses as much as digits as its factorization.

21462421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 69322.

The product of its digits is 768, while the sum is 22.

The square root of 21462421 is about 4632.7552277236. The cubic root of 21462421 is about 277.9027876379.

Adding to 21462421 its reverse (12426412), we get a palindrome (33888833).

The spelling of 21462421 in words is "twenty-one million, four hundred sixty-two thousand, four hundred twenty-one".