20505512003 has 4 divisors (see below), whose sum is σ = 20521396728. Its totient is φ = 20489627280.

The previous prime is 20505511933. The next prime is 20505512011. The reversal of 20505512003 is 30021550502.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20505512003 - 2¹⁰ = 20505510979 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 20505512003.

It is not an unprimeable number, because it can be changed into a prime (20505512303) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7940426 + ... + 7943007.

It is an arithmetic number, because the mean of its divisors is an integer number (5130349182).

Almost surely, 2^20505512003 is an apocalyptic number.

20505512003 is a deficient number, since it is larger than the sum of its proper divisors (15884725).

20505512003 is a wasteful number, since it uses less digits than its factorization.

20505512003 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15884724.

The product of its (nonzero) digits is 1500, while the sum is 23.

The spelling of 20505512003 in words is "twenty billion, five hundred five million, five hundred twelve thousand, three".