21273015 has 8 divisors (see below), whose sum is σ = 34036848. Its totient is φ = 11345600.

The previous prime is 21273013. The next prime is 21273017. The reversal of 21273015 is 51037212.

It is an interprime number because it is at equal distance from previous prime (21273013) and next prime (21273017).

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

It is not a de Polignac number, because 21273015 - 2¹ = 21273013 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21272982 and 21273000.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21273011) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 709086 + ... + 709115.

It is an arithmetic number, because the mean of its divisors is an integer number (4254606).

Almost surely, 2^21273015 is an apocalyptic number.

21273015 is a deficient number, since it is larger than the sum of its proper divisors (12763833).

21273015 is a wasteful number, since it uses less digits than its factorization.

21273015 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1418209.

The product of its (nonzero) digits is 420, while the sum is 21.

The square root of 21273015 is about 4612.2678803383. The cubic root of 21273015 is about 277.0828730214.

The spelling of 21273015 in words is "twenty-one million, two hundred seventy-three thousand, fifteen".