21675237539 has 2 divisors, whose sum is σ = 21675237540. Its totient is φ = 21675237538.

The previous prime is 21675237509. The next prime is 21675237583. The reversal of 21675237539 is 93573257612.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21675237539 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (21675237509) 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, 10837618769 + 10837618770.

It is an arithmetic number, because the mean of its divisors is an integer number (10837618770).

Almost surely, 2^21675237539 is an apocalyptic number.

21675237539 is a deficient number, since it is larger than the sum of its proper divisors (1).

21675237539 is an equidigital number, since it uses as much as digits as its factorization.

21675237539 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2381400, while the sum is 50.

The spelling of 21675237539 in words is "twenty-one billion, six hundred seventy-five million, two hundred thirty-seven thousand, five hundred thirty-nine".