91516407991 has 2 divisors, whose sum is σ = 91516407992. Its totient is φ = 91516407990.

The previous prime is 91516407967. The next prime is 91516408013. The reversal of 91516407991 is 19970461519.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 91516407991 - 2⁵ = 91516407959 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91516407691) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45758203995 + 45758203996.

It is an arithmetic number, because the mean of its divisors is an integer number (45758203996).

Almost surely, 2^91516407991 is an apocalyptic number.

91516407991 is a deficient number, since it is larger than the sum of its proper divisors (1).

91516407991 is an equidigital number, since it uses as much as digits as its factorization.

91516407991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 612360, while the sum is 52.

The spelling of 91516407991 in words is "ninety-one billion, five hundred sixteen million, four hundred seven thousand, nine hundred ninety-one".