21749149625171 has 2 divisors, whose sum is σ = 21749149625172. Its totient is φ = 21749149625170.

The previous prime is 21749149625111. The next prime is 21749149625197. The reversal of 21749149625171 is 17152694194712.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21749149625171 - 2³⁴ = 21731969755987 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21749149625171.

It is not a weakly prime, because it can be changed into another prime (21749149625111) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10874574812585 + 10874574812586.

It is an arithmetic number, because the mean of its divisors is an integer number (10874574812586).

Almost surely, 2^{21749149625171} is an apocalyptic number.

21749149625171 is a deficient number, since it is larger than the sum of its proper divisors (1).

21749149625171 is an equidigital number, since it uses as much as digits as its factorization.

21749149625171 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7620480, while the sum is 59.

The spelling of 21749149625171 in words is "twenty-one trillion, seven hundred forty-nine billion, one hundred forty-nine million, six hundred twenty-five thousand, one hundred seventy-one".