21246047 has 8 divisors (see below), whose sum is σ = 22492800. Its totient is φ = 20012184.

The previous prime is 21245981. The next prime is 21246053. The reversal of 21246047 is 74064212.

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

It is a cyclic number.

It is not a de Polignac number, because 21246047 - 2¹² = 21241951 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21246947) 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, 278 + ... + 6524.

It is an arithmetic number, because the mean of its divisors is an integer number (2811600).

Almost surely, 2^21246047 is an apocalyptic number.

21246047 is a deficient number, since it is larger than the sum of its proper divisors (1246753).

21246047 is a wasteful number, since it uses less digits than its factorization.

21246047 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6445.

The product of its (nonzero) digits is 2688, while the sum is 26.

The square root of 21246047 is about 4609.3434456547. The cubic root of 21246047 is about 276.9657366596.

The spelling of 21246047 in words is "twenty-one million, two hundred forty-six thousand, forty-seven".