65761800991 has 2 divisors, whose sum is σ = 65761800992. Its totient is φ = 65761800990.

The previous prime is 65761800943. The next prime is 65761801003. The reversal of 65761800991 is 19900816756.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 65761800991 - 2⁹ = 65761800479 is a prime.

It is a super-3 number, since 3×65761800991³ (a number of 33 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (65761800691) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32880900495 + 32880900496.

It is an arithmetic number, because the mean of its divisors is an integer number (32880900496).

Almost surely, 2^65761800991 is an apocalyptic number.

65761800991 is a deficient number, since it is larger than the sum of its proper divisors (1).

65761800991 is an equidigital number, since it uses as much as digits as its factorization.

65761800991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 816480, while the sum is 52.

The spelling of 65761800991 in words is "sixty-five billion, seven hundred sixty-one million, eight hundred thousand, nine hundred ninety-one".