21424867 has 4 divisors (see below), whose sum is σ = 21434760. Its totient is φ = 21414976.

The previous prime is 21424861. The next prime is 21424877. The reversal of 21424867 is 76842412.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 21424867 - 2¹⁵ = 21392099 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21424861) 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, 142 + ... + 6547.

It is an arithmetic number, because the mean of its divisors is an integer number (5358690).

Almost surely, 2^21424867 is an apocalyptic number.

21424867 is a deficient number, since it is larger than the sum of its proper divisors (9893).

21424867 is an equidigital number, since it uses as much as digits as its factorization.

21424867 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9892.

The product of its digits is 21504, while the sum is 34.

The square root of 21424867 is about 4628.7003575518. The cubic root of 21424867 is about 277.7406056510.

The spelling of 21424867 in words is "twenty-one million, four hundred twenty-four thousand, eight hundred sixty-seven".