91861768619 has 4 divisors (see below), whose sum is σ = 91876353840. Its totient is φ = 91847183400.

The previous prime is 91861768573. The next prime is 91861768627. The reversal of 91861768619 is 91686716819.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 91686716819 = 3539 ⋅25907521.

It is a cyclic number.

It is not a de Polignac number, because 91861768619 - 2¹² = 91861764523 is a prime.

It is a super-2 number, since 2×91861768619² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (91861768519) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7283159 + ... + 7295760.

It is an arithmetic number, because the mean of its divisors is an integer number (22969088460).

Almost surely, 2^91861768619 is an apocalyptic number.

91861768619 is a deficient number, since it is larger than the sum of its proper divisors (14585221).

91861768619 is a wasteful number, since it uses less digits than its factorization.

91861768619 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14585220.

The product of its digits is 7838208, while the sum is 62.

The spelling of 91861768619 in words is "ninety-one billion, eight hundred sixty-one million, seven hundred sixty-eight thousand, six hundred nineteen".