21424015 has 8 divisors (see below), whose sum is σ = 25735248. Its totient is φ = 17121600.

The previous prime is 21424003. The next prime is 21424027. The reversal of 21424015 is 51042412.

It is an interprime number because it is at equal distance from previous prime (21424003) and next prime (21424027).

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

It is not a de Polignac number, because 21424015 - 2²¹ = 19326863 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21423983 and 21424001.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5779 + ... + 8731.

It is an arithmetic number, because the mean of its divisors is an integer number (3216906).

Almost surely, 2^21424015 is an apocalyptic number.

21424015 is a deficient number, since it is larger than the sum of its proper divisors (4311233).

21424015 is a wasteful number, since it uses less digits than its factorization.

21424015 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4409.

The product of its (nonzero) digits is 320, while the sum is 19.

The square root of 21424015 is about 4628.6083221634. The cubic root of 21424015 is about 277.7369239770.

Adding to 21424015 its reverse (51042412), we get a palindrome (72466427).

The spelling of 21424015 in words is "twenty-one million, four hundred twenty-four thousand, fifteen".