21130139 has 4 divisors (see below), whose sum is σ = 21240960. Its totient is φ = 21019320.

The previous prime is 21130111. The next prime is 21130231. The reversal of 21130139 is 93103112.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21130139 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 21130139.

It is not an unprimeable number, because it can be changed into a prime (21130939) 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 3 ways as a sum of consecutive naturals, for example, 55124 + ... + 55505.

It is an arithmetic number, because the mean of its divisors is an integer number (5310240).

Almost surely, 2^21130139 is an apocalyptic number.

21130139 is a deficient number, since it is larger than the sum of its proper divisors (110821).

21130139 is a wasteful number, since it uses less digits than its factorization.

21130139 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 110820.

The product of its (nonzero) digits is 162, while the sum is 20.

The square root of 21130139 is about 4596.7530932170. The cubic root of 21130139 is about 276.4611549405.

The spelling of 21130139 in words is "twenty-one million, one hundred thirty thousand, one hundred thirty-nine".