21545149319 has 2 divisors, whose sum is σ = 21545149320. Its totient is φ = 21545149318.

The previous prime is 21545149273. The next prime is 21545149333. The reversal of 21545149319 is 91394154512.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21545149319 is a prime.

It is a super-2 number, since 2×21545149319² (a number of 21 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21545149319.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21545149349) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10772574659 + 10772574660.

It is an arithmetic number, because the mean of its divisors is an integer number (10772574660).

Almost surely, 2^21545149319 is an apocalyptic number.

21545149319 is a deficient number, since it is larger than the sum of its proper divisors (1).

21545149319 is an equidigital number, since it uses as much as digits as its factorization.

21545149319 is an evil number, because the sum of its binary digits is even.

The product of its digits is 194400, while the sum is 44.

The spelling of 21545149319 in words is "twenty-one billion, five hundred forty-five million, one hundred forty-nine thousand, three hundred nineteen".