21415047 has 8 divisors (see below), whose sum is σ = 29794944. Its totient is φ = 13655928.

The previous prime is 21415027. The next prime is 21415067. The reversal of 21415047 is 74051412.

It is an interprime number because it is at equal distance from previous prime (21415027) and next prime (21415067).

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

It is not a de Polignac number, because 21415047 - 2⁶ = 21414983 is a prime.

It is a Smith number, since the sum of its digits (24) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21415027) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 155113 + ... + 155250.

It is an arithmetic number, because the mean of its divisors is an integer number (3724368).

Almost surely, 2^21415047 is an apocalyptic number.

21415047 is a deficient number, since it is larger than the sum of its proper divisors (8379897).

21415047 is a wasteful number, since it uses less digits than its factorization.

21415047 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 310389.

The product of its (nonzero) digits is 1120, while the sum is 24.

The square root of 21415047 is about 4627.6394630524. The cubic root of 21415047 is about 277.6981654101.

Adding to 21415047 its reverse (74051412), we get a palindrome (95466459).

The spelling of 21415047 in words is "twenty-one million, four hundred fifteen thousand, forty-seven".