21877131206317 has 2 divisors, whose sum is σ = 21877131206318. Its totient is φ = 21877131206316.

The previous prime is 21877131206297. The next prime is 21877131206401. The reversal of 21877131206317 is 71360213177812.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19245163598761 + 2631967607556 = 4386931^2 + 1622334^2 .

It is a cyclic number.

It is not a de Polignac number, because 21877131206317 - 2²³ = 21877122817709 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21877131200317) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10938565603158 + 10938565603159.

It is an arithmetic number, because the mean of its divisors is an integer number (10938565603159).

Almost surely, 2^{21877131206317} is an apocalyptic number.

It is an amenable number.

21877131206317 is a deficient number, since it is larger than the sum of its proper divisors (1).

21877131206317 is an equidigital number, since it uses as much as digits as its factorization.

21877131206317 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 592704, while the sum is 49.

The spelling of 21877131206317 in words is "twenty-one trillion, eight hundred seventy-seven billion, one hundred thirty-one million, two hundred six thousand, three hundred seventeen".