21203002313 has 4 divisors (see below), whose sum is σ = 21397525380. Its totient is φ = 21008479248.

The previous prime is 21203002231. The next prime is 21203002391. The reversal of 21203002313 is 31320030212.

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 19299599929 + 1903402384 = 138923^2 + 43628^2 .

It is a cyclic number.

It is not a de Polignac number, because 21203002313 - 2³² = 16908035017 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21203002291 and 21203002300.

It is not an unprimeable number, because it can be changed into a prime (21203602313) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 97261370 + ... + 97261587.

It is an arithmetic number, because the mean of its divisors is an integer number (5349381345).

Almost surely, 2^21203002313 is an apocalyptic number.

It is an amenable number.

21203002313 is a deficient number, since it is larger than the sum of its proper divisors (194523067).

21203002313 is a wasteful number, since it uses less digits than its factorization.

21203002313 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 194523066.

The product of its (nonzero) digits is 216, while the sum is 17.

Adding to 21203002313 its reverse (31320030212), we get a palindrome (52523032525).

The spelling of 21203002313 in words is "twenty-one billion, two hundred three million, two thousand, three hundred thirteen".