21153499187 has 2 divisors, whose sum is σ = 21153499188. Its totient is φ = 21153499186.

The previous prime is 21153499151. The next prime is 21153499207. The reversal of 21153499187 is 78199435112.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21153499187 - 2¹² = 21153495091 is a prime.

It is not a weakly prime, because it can be changed into another prime (21153469187) 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, 10576749593 + 10576749594.

It is an arithmetic number, because the mean of its divisors is an integer number (10576749594).

Almost surely, 2^21153499187 is an apocalyptic number.

21153499187 is a deficient number, since it is larger than the sum of its proper divisors (1).

21153499187 is an equidigital number, since it uses as much as digits as its factorization.

21153499187 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 544320, while the sum is 50.

The spelling of 21153499187 in words is "twenty-one billion, one hundred fifty-three million, four hundred ninety-nine thousand, one hundred eighty-seven".