21046215 has 8 divisors (see below), whose sum is σ = 33673968. Its totient is φ = 11224640.

The previous prime is 21046171. The next prime is 21046217. The reversal of 21046215 is 51264012.

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

It is not a de Polignac number, because 21046215 - 2¹³ = 21038023 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21046191 and 21046200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21046217) 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, 701526 + ... + 701555.

It is an arithmetic number, because the mean of its divisors is an integer number (4209246).

Almost surely, 2^21046215 is an apocalyptic number.

21046215 is a deficient number, since it is larger than the sum of its proper divisors (12627753).

21046215 is a wasteful number, since it uses less digits than its factorization.

21046215 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1403089.

The product of its (nonzero) digits is 480, while the sum is 21.

The square root of 21046215 is about 4587.6153936441. The cubic root of 21046215 is about 276.0946561491.

The spelling of 21046215 in words is "twenty-one million, forty-six thousand, two hundred fifteen".