91378222087 has 4 divisors (see below), whose sum is σ = 92742076216. Its totient is φ = 90014367960.

The previous prime is 91378222079. The next prime is 91378222099. The reversal of 91378222087 is 78022287319.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 78022287319 = 52583 ⋅1483793.

It is a cyclic number.

It is not a de Polignac number, because 91378222087 - 2³ = 91378222079 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 91378222087.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91378222057) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 681926964 + ... + 681927097.

It is an arithmetic number, because the mean of its divisors is an integer number (23185519054).

Almost surely, 2^91378222087 is an apocalyptic number.

91378222087 is a deficient number, since it is larger than the sum of its proper divisors (1363854129).

91378222087 is a wasteful number, since it uses less digits than its factorization.

91378222087 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1363854128.

The product of its (nonzero) digits is 677376, while the sum is 49.

The spelling of 91378222087 in words is "ninety-one billion, three hundred seventy-eight million, two hundred twenty-two thousand, eighty-seven".