21093015 has 16 divisors (see below), whose sum is σ = 33959808. Its totient is φ = 11179296.

The previous prime is 21093013. The next prime is 21093019. The reversal of 21093015 is 51039012.

It is not a de Polignac number, because 21093015 - 2¹ = 21093013 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21092982 and 21093000.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21093011) 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 15 ways as a sum of consecutive naturals, for example, 1869 + ... + 6758.

It is an arithmetic number, because the mean of its divisors is an integer number (2122488).

Almost surely, 2^21093015 is an apocalyptic number.

21093015 is a deficient number, since it is larger than the sum of its proper divisors (12866793).

21093015 is a wasteful number, since it uses less digits than its factorization.

21093015 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8798.

The product of its (nonzero) digits is 270, while the sum is 21.

The square root of 21093015 is about 4592.7132503565. The cubic root of 21093015 is about 276.2991531600.

The spelling of 21093015 in words is "twenty-one million, ninety-three thousand, fifteen".