918786378691 has 4 divisors (see below), whose sum is σ = 931727031984. Its totient is φ = 905845725400.

The previous prime is 918786378683. The next prime is 918786378761. The reversal of 918786378691 is 196873687819.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 196873687819 = 16759 ⋅11747341.

It is a cyclic number.

It is not a de Polignac number, because 918786378691 - 2³ = 918786378683 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (918786378611) 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, 6470326540 + ... + 6470326681.

It is an arithmetic number, because the mean of its divisors is an integer number (232931757996).

Almost surely, 2^918786378691 is an apocalyptic number.

918786378691 is a deficient number, since it is larger than the sum of its proper divisors (12940653293).

918786378691 is a wasteful number, since it uses less digits than its factorization.

918786378691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12940653292.

The product of its digits is 219469824, while the sum is 73.

The spelling of 918786378691 in words is "nine hundred eighteen billion, seven hundred eighty-six million, three hundred seventy-eight thousand, six hundred ninety-one".