20021439 has 8 divisors (see below), whose sum is σ = 27199152. Its totient is φ = 13095680.

The previous prime is 20021429. The next prime is 20021467. The reversal of 20021439 is 93412002.

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 20021439 - 2⁷ = 20021311 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20021429) 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, 62802 + ... + 63119.

It is an arithmetic number, because the mean of its divisors is an integer number (3399894).

Almost surely, 2^20021439 is an apocalyptic number.

20021439 is a deficient number, since it is larger than the sum of its proper divisors (7177713).

20021439 is a wasteful number, since it uses less digits than its factorization.

20021439 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 125977.

The product of its (nonzero) digits is 432, while the sum is 21.

The square root of 20021439 is about 4474.5322660587. The cubic root of 20021439 is about 271.5387176892.

The spelling of 20021439 in words is "twenty million, twenty-one thousand, four hundred thirty-nine".