21252039 has 8 divisors (see below), whose sum is σ = 28401792. Its totient is φ = 14135160.

The previous prime is 21252031. The next prime is 21252047. The reversal of 21252039 is 93025212.

It is an interprime number because it is at equal distance from previous prime (21252031) and next prime (21252047).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21252039 - 2³ = 21252031 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21252031) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6667 + ... + 9324.

It is an arithmetic number, because the mean of its divisors is an integer number (3550224).

Almost surely, 2^21252039 is an apocalyptic number.

21252039 is a deficient number, since it is larger than the sum of its proper divisors (7149753).

21252039 is a wasteful number, since it uses less digits than its factorization.

21252039 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16437.

The product of its (nonzero) digits is 1080, while the sum is 24.

The square root of 21252039 is about 4609.9933839432. The cubic root of 21252039 is about 276.9917716628.

It can be divided in two parts, 2125203 and 9, that added together give a palindrome (2125212).

The spelling of 21252039 in words is "twenty-one million, two hundred fifty-two thousand, thirty-nine".