21093507 has 16 divisors (see below), whose sum is σ = 32609280. Its totient is φ = 13450536.

The previous prime is 21093493. The next prime is 21093509. The reversal of 21093507 is 70539012.

It is not a de Polignac number, because 21093507 - 2⁴ = 21093491 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (21093509) 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 15 ways as a sum of consecutive naturals, for example, 16363 + ... + 17604.

It is an arithmetic number, because the mean of its divisors is an integer number (2038080).

Almost surely, 2^21093507 is an apocalyptic number.

21093507 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

21093507 is a deficient number, since it is larger than the sum of its proper divisors (11515773).

21093507 is a wasteful number, since it uses less digits than its factorization.

21093507 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33999 (or 33993 counting only the distinct ones).

The product of its (nonzero) digits is 1890, while the sum is 27.

The square root of 21093507 is about 4592.7668131530. The cubic root of 21093507 is about 276.3013013929.

The spelling of 21093507 in words is "twenty-one million, ninety-three thousand, five hundred seven".