21004131013 has 2 divisors, whose sum is σ = 21004131014. Its totient is φ = 21004131012.

The previous prime is 21004130971. The next prime is 21004131017. The reversal of 21004131013 is 31013140012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14060742084 + 6943388929 = 118578^2 + 83327^2 .

It is a cyclic number.

It is not a de Polignac number, because 21004131013 - 2⁹ = 21004130501 is a prime.

It is a super-2 number, since 2×21004131013² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21004131017) 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 as a sum of consecutive naturals, namely, 10502065506 + 10502065507.

It is an arithmetic number, because the mean of its divisors is an integer number (10502065507).

Almost surely, 2^21004131013 is an apocalyptic number.

It is an amenable number.

21004131013 is a deficient number, since it is larger than the sum of its proper divisors (1).

21004131013 is an equidigital number, since it uses as much as digits as its factorization.

21004131013 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 72, while the sum is 16.

Adding to 21004131013 its reverse (31013140012), we get a palindrome (52017271025).

The spelling of 21004131013 in words is "twenty-one billion, four million, one hundred thirty-one thousand, thirteen".