21004631313 has 4 divisors (see below), whose sum is σ = 28006175088. Its totient is φ = 14003087540.

The previous prime is 21004631293. The next prime is 21004631317. The reversal of 21004631313 is 31313640012.

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 a cyclic number.

It is not a de Polignac number, because 21004631313 - 2⁸ = 21004631057 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21004631317) 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, 3500771883 + ... + 3500771888.

It is an arithmetic number, because the mean of its divisors is an integer number (7001543772).

Almost surely, 2^21004631313 is an apocalyptic number.

It is an amenable number.

21004631313 is a deficient number, since it is larger than the sum of its proper divisors (7001543775).

21004631313 is an equidigital number, since it uses as much as digits as its factorization.

21004631313 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7001543774.

The product of its (nonzero) digits is 1296, while the sum is 24.

The spelling of 21004631313 in words is "twenty-one billion, four million, six hundred thirty-one thousand, three hundred thirteen".