21020003013 has 4 divisors (see below), whose sum is σ = 28026670688. Its totient is φ = 14013335340.

The previous prime is 21020002987. The next prime is 21020003027. The reversal of 21020003013 is 31030002012.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 21020003013 - 2¹⁷ = 21019871941 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 21020003013.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21020003033) 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, 3503333833 + ... + 3503333838.

It is an arithmetic number, because the mean of its divisors is an integer number (7006667672).

Almost surely, 2^21020003013 is an apocalyptic number.

It is an amenable number.

21020003013 is a deficient number, since it is larger than the sum of its proper divisors (7006667675).

21020003013 is an equidigital number, since it uses as much as digits as its factorization.

21020003013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7006667674.

The product of its (nonzero) digits is 36, while the sum is 12.

Adding to 21020003013 its reverse (31030002012), we get a palindrome (52050005025).

The spelling of 21020003013 in words is "twenty-one billion, twenty million, three thousand, thirteen".