21174813677 has 2 divisors, whose sum is σ = 21174813678. Its totient is φ = 21174813676.

The previous prime is 21174813601. The next prime is 21174813713. The reversal of 21174813677 is 77631847112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18862550281 + 2312263396 = 137341^2 + 48086^2 .

It is a cyclic number.

It is not a de Polignac number, because 21174813677 - 2²⁰ = 21173765101 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21174813277) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10587406838 + 10587406839.

It is an arithmetic number, because the mean of its divisors is an integer number (10587406839).

Almost surely, 2^21174813677 is an apocalyptic number.

It is an amenable number.

21174813677 is a deficient number, since it is larger than the sum of its proper divisors (1).

21174813677 is an equidigital number, since it uses as much as digits as its factorization.

21174813677 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 395136, while the sum is 47.

The spelling of 21174813677 in words is "twenty-one billion, one hundred seventy-four million, eight hundred thirteen thousand, six hundred seventy-seven".