20642439 has 8 divisors (see below), whose sum is σ = 27554032. Its totient is φ = 13746240.

The previous prime is 20642423. The next prime is 20642443. The reversal of 20642439 is 93424602.

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

It is not a de Polignac number, because 20642439 - 2⁴ = 20642423 is a prime.

It is a super-2 number, since 2×20642439² = 852220575737442, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20642449) 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, 232 + ... + 6429.

It is an arithmetic number, because the mean of its divisors is an integer number (3444254).

Almost surely, 2^20642439 is an apocalyptic number.

20642439 is a deficient number, since it is larger than the sum of its proper divisors (6911593).

20642439 is a wasteful number, since it uses less digits than its factorization.

20642439 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7697.

The product of its (nonzero) digits is 10368, while the sum is 30.

The square root of 20642439 is about 4543.3950961808. The cubic root of 20642439 is about 274.3175984063.

The spelling of 20642439 in words is "twenty million, six hundred forty-two thousand, four hundred thirty-nine".