21092539 has 8 divisors (see below), whose sum is σ = 22776320. Its totient is φ = 19417536.

The previous prime is 21092507. The next prime is 21092543. The reversal of 21092539 is 93529012.

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 21092539 - 2⁵ = 21092507 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21092539.

It is not an unprimeable number, because it can be changed into a prime (21092549) 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, 3334 + ... + 7300.

It is an arithmetic number, because the mean of its divisors is an integer number (2847040).

Almost surely, 2^21092539 is an apocalyptic number.

21092539 is a deficient number, since it is larger than the sum of its proper divisors (1683781).

21092539 is a wasteful number, since it uses less digits than its factorization.

21092539 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4389.

The product of its (nonzero) digits is 4860, while the sum is 31.

The square root of 21092539 is about 4592.6614288449. The cubic root of 21092539 is about 276.2970747565.

The spelling of 21092539 in words is "twenty-one million, ninety-two thousand, five hundred thirty-nine".