188661262719991 has 2 divisors, whose sum is σ = 188661262719992. Its totient is φ = 188661262719990.

The previous prime is 188661262719977. The next prime is 188661262720031. The reversal of 188661262719991 is 199917262166881.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 188661262719991 - 2⁵ = 188661262719959 is a prime.

It is a super-2 number, since 2×188661262719991² (a number of 29 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (188661262719911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 94330631359995 + 94330631359996.

It is an arithmetic number, because the mean of its divisors is an integer number (94330631359996).

Almost surely, 2^{188661262719991} is an apocalyptic number.

188661262719991 is a deficient number, since it is larger than the sum of its proper divisors (1).

188661262719991 is an equidigital number, since it uses as much as digits as its factorization.

188661262719991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 282175488, while the sum is 76.

The spelling of 188661262719991 in words is "one hundred eighty-eight trillion, six hundred sixty-one billion, two hundred sixty-two million, seven hundred nineteen thousand, nine hundred ninety-one".