20001539 has 8 divisors (see below), whose sum is σ = 20227200. Its totient is φ = 19777536.

The previous prime is 20001521. The next prime is 20001551. The reversal of 20001539 is 93510002.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20001539 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20001539.

It is not an unprimeable number, because it can be changed into a prime (20001139) 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, 57137 + ... + 57485.

It is an arithmetic number, because the mean of its divisors is an integer number (2528400).

Almost surely, 2^20001539 is an apocalyptic number.

20001539 is a deficient number, since it is larger than the sum of its proper divisors (225661).

20001539 is a wasteful number, since it uses less digits than its factorization.

20001539 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 829.

The product of its (nonzero) digits is 270, while the sum is 20.

The square root of 20001539 is about 4472.3080171205. The cubic root of 20001539 is about 271.4487239621.

The spelling of 20001539 in words is "twenty million, one thousand, five hundred thirty-nine".