91387929865 has 16 divisors (see below), whose sum is σ = 115544602368. Its totient is φ = 69252676416.

The previous prime is 91387929863. The next prime is 91387929869. The reversal of 91387929865 is 56892978319.

It is a cyclic number.

It is not a de Polignac number, because 91387929865 - 2¹ = 91387929863 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 91387929865.

It is not an unprimeable number, because it can be changed into a prime (91387929863) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3845814 + ... + 3869503.

It is an arithmetic number, because the mean of its divisors is an integer number (7221537648).

Almost surely, 2^91387929865 is an apocalyptic number.

It is an amenable number.

91387929865 is a deficient number, since it is larger than the sum of its proper divisors (24156672503).

91387929865 is a wasteful number, since it uses less digits than its factorization.

91387929865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7715448.

The product of its digits is 58786560, while the sum is 67.

The spelling of 91387929865 in words is "ninety-one billion, three hundred eighty-seven million, nine hundred twenty-nine thousand, eight hundred sixty-five".