21013123313 has 16 divisors (see below), whose sum is σ = 25866266496. Its totient is φ = 16623221760.

The previous prime is 21013123247. The next prime is 21013123331. The reversal of 21013123313 is 31332131012.

It is a cyclic number.

It is not a de Polignac number, because 21013123313 - 2²⁰ = 21012074737 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21013123333) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 772970 + ... + 799692.

It is an arithmetic number, because the mean of its divisors is an integer number (1616641656).

Almost surely, 2^21013123313 is an apocalyptic number.

It is an amenable number.

21013123313 is a deficient number, since it is larger than the sum of its proper divisors (4853143183).

21013123313 is a wasteful number, since it uses less digits than its factorization.

21013123313 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35384.

The product of its (nonzero) digits is 324, while the sum is 20.

Adding to 21013123313 its reverse (31332131012), we get a palindrome (52345254325).

The spelling of 21013123313 in words is "twenty-one billion, thirteen million, one hundred twenty-three thousand, three hundred thirteen".