21023040013 has 4 divisors (see below), whose sum is σ = 21083278300. Its totient is φ = 20962801728.

The previous prime is 21023039959. The next prime is 21023040019. The reversal of 21023040013 is 31004032012.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 7098568009 + 13924472004 = 84253^2 + 118002^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21023040013 is a prime.

It is a super-2 number, since 2×21023040013² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21023040019) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 30118620 + ... + 30119317.

It is an arithmetic number, because the mean of its divisors is an integer number (5270819575).

Almost surely, 2^21023040013 is an apocalyptic number.

It is an amenable number.

21023040013 is a deficient number, since it is larger than the sum of its proper divisors (60238287).

21023040013 is an equidigital number, since it uses as much as digits as its factorization.

21023040013 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 60238286.

The product of its (nonzero) digits is 144, while the sum is 16.

Adding to 21023040013 its reverse (31004032012), we get a palindrome (52027072025).

The spelling of 21023040013 in words is "twenty-one billion, twenty-three million, forty thousand, thirteen".