21123130213 has 8 divisors (see below), whose sum is σ = 21346837848. Its totient is φ = 20899544064.

The previous prime is 21123130153. The next prime is 21123130219. The reversal of 21123130213 is 31203132112.

It can be written as a sum of positive squares in 4 ways, for example, as 5861739844 + 15261390369 = 76562^2 + 123537^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 21123130213 - 2¹³ = 21123122021 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21123130219) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 343395 + ... + 400207.

It is an arithmetic number, because the mean of its divisors is an integer number (2668354731).

Almost surely, 2^21123130213 is an apocalyptic number.

It is an amenable number.

21123130213 is a deficient number, since it is larger than the sum of its proper divisors (223707635).

21123130213 is an equidigital number, since it uses as much as digits as its factorization.

21123130213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 60743.

The product of its (nonzero) digits is 216, while the sum is 19.

Adding to 21123130213 its reverse (31203132112), we get a palindrome (52326262325).

The spelling of 21123130213 in words is "twenty-one billion, one hundred twenty-three million, one hundred thirty thousand, two hundred thirteen".