391475777136 has 80 divisors (see below), whose sum is σ = 1024769410560. Its totient is φ = 128757657600.

The previous prime is 391475777129. The next prime is 391475777137. The reversal of 391475777136 is 631777574193.

It is a Smith number, since the sum of its digits (60) coincides with the sum of the digits of its prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 391475777136.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (391475777137) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6038751 + ... + 6103233.

It is an arithmetic number, because the mean of its divisors is an integer number (12809617632).

Almost surely, 2^391475777136 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 391475777136, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (512384705280).

391475777136 is an abundant number, since it is smaller than the sum of its proper divisors (633293633424).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

391475777136 is a wasteful number, since it uses less digits than its factorization.

391475777136 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66174 (or 66168 counting only the distinct ones).

The product of its digits is 23337720, while the sum is 60.

It can be divided in two parts, 391475 and 777136, that added together give a palindrome (1168611).

The spelling of 391475777136 in words is "three hundred ninety-one billion, four hundred seventy-five million, seven hundred seventy-seven thousand, one hundred thirty-six".