91387929895 has 4 divisors (see below), whose sum is σ = 109665515880. Its totient is φ = 73110343912.

The previous prime is 91387929869. The next prime is 91387929907. The reversal of 91387929895 is 59892978319.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 59892978319 = 5101 ⋅11741419.

It is a cyclic number.

It is not a de Polignac number, because 91387929895 - 2⁵ = 91387929863 is a prime.

It is a super-2 number, since 2×91387929895² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9138792985 + ... + 9138792994.

It is an arithmetic number, because the mean of its divisors is an integer number (27416378970).

Almost surely, 2^91387929895 is an apocalyptic number.

91387929895 is a deficient number, since it is larger than the sum of its proper divisors (18277585985).

91387929895 is a wasteful number, since it uses less digits than its factorization.

91387929895 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18277585984.

The product of its digits is 88179840, while the sum is 70.

The spelling of 91387929895 in words is "ninety-one billion, three hundred eighty-seven million, nine hundred twenty-nine thousand, eight hundred ninety-five".