20442539 has 8 divisors (see below), whose sum is σ = 22132992. Its totient is φ = 18768960.

The previous prime is 20442523. The next prime is 20442557. The reversal of 20442539 is 93524402.

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 20442539 - 2⁴ = 20442523 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20442589) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1634 + ... + 6599.

It is an arithmetic number, because the mean of its divisors is an integer number (2766624).

Almost surely, 2^20442539 is an apocalyptic number.

20442539 is a deficient number, since it is larger than the sum of its proper divisors (1690453).

20442539 is a wasteful number, since it uses less digits than its factorization.

20442539 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8437.

The product of its (nonzero) digits is 8640, while the sum is 29.

The square root of 20442539 is about 4521.3426103316. The cubic root of 20442539 is about 273.4292334851.

The spelling of 20442539 in words is "twenty million, four hundred forty-two thousand, five hundred thirty-nine".