21531313103 has 2 divisors, whose sum is σ = 21531313104. Its totient is φ = 21531313102.

The previous prime is 21531313079. The next prime is 21531313121. The reversal of 21531313103 is 30131313512.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21531313103 - 2⁶ = 21531313039 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21531310103) 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, 10765656551 + 10765656552.

It is an arithmetic number, because the mean of its divisors is an integer number (10765656552).

Almost surely, 2^21531313103 is an apocalyptic number.

21531313103 is a deficient number, since it is larger than the sum of its proper divisors (1).

21531313103 is an equidigital number, since it uses as much as digits as its factorization.

21531313103 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 810, while the sum is 23.

Adding to 21531313103 its reverse (30131313512), we get a palindrome (51662626615).

The spelling of 21531313103 in words is "twenty-one billion, five hundred thirty-one million, three hundred thirteen thousand, one hundred three".