91973609879 has 2 divisors, whose sum is σ = 91973609880. Its totient is φ = 91973609878.

The previous prime is 91973609839. The next prime is 91973609891. The reversal of 91973609879 is 97890637919.

It is a strong prime.

It is an emirp because it is prime and its reverse (97890637919) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 91973609879 - 2¹² = 91973605783 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91973609839) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45986804939 + 45986804940.

It is an arithmetic number, because the mean of its divisors is an integer number (45986804940).

Almost surely, 2^91973609879 is an apocalyptic number.

91973609879 is a deficient number, since it is larger than the sum of its proper divisors (1).

91973609879 is an equidigital number, since it uses as much as digits as its factorization.

91973609879 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 46294416, while the sum is 68.

The spelling of 91973609879 in words is "ninety-one billion, nine hundred seventy-three million, six hundred nine thousand, eight hundred seventy-nine".