21150039 has 4 divisors (see below), whose sum is σ = 28200056. Its totient is φ = 14100024.

The previous prime is 21150037. The next prime is 21150043. The reversal of 21150039 is 93005112.

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

It is not a de Polignac number, because 21150039 - 2¹ = 21150037 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21149997 and 21150024.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21150037) 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, 3525004 + ... + 3525009.

It is an arithmetic number, because the mean of its divisors is an integer number (7050014).

Almost surely, 2^21150039 is an apocalyptic number.

21150039 is a deficient number, since it is larger than the sum of its proper divisors (7050017).

21150039 is an equidigital number, since it uses as much as digits as its factorization.

21150039 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7050016.

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

The square root of 21150039 is about 4598.9171551573. The cubic root of 21150039 is about 276.5479164898.

The spelling of 21150039 in words is "twenty-one million, one hundred fifty thousand, thirty-nine".