21375391523 has 2 divisors, whose sum is σ = 21375391524. Its totient is φ = 21375391522.

The previous prime is 21375391487. The next prime is 21375391549. The reversal of 21375391523 is 32519357312.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21375391523 - 2¹⁴ = 21375375139 is a prime.

It is not a weakly prime, because it can be changed into another prime (21375391823) 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 as a sum of consecutive naturals, namely, 10687695761 + 10687695762.

It is an arithmetic number, because the mean of its divisors is an integer number (10687695762).

Almost surely, 2^21375391523 is an apocalyptic number.

21375391523 is a deficient number, since it is larger than the sum of its proper divisors (1).

21375391523 is an equidigital number, since it uses as much as digits as its factorization.

21375391523 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 170100, while the sum is 41.

The spelling of 21375391523 in words is "twenty-one billion, three hundred seventy-five million, three hundred ninety-one thousand, five hundred twenty-three".