391643997696 has 640 divisors, whose sum is σ = 1401493632000. Its totient is φ = 105488842752.

The previous prime is 391643997683. The next prime is 391643997737. The reversal of 391643997696 is 696799346193.

391643997696 is a `hidden beast` number, since 3 + 9 + 16 + 439 + 97 + 6 + 96 = 666.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 509289600 + ... + 509290368.

It is an arithmetic number, because the mean of its divisors is an integer number (2189833800).

Almost surely, 2^391643997696 is an apocalyptic number.

391643997696 is a gapful number since it is divisible by the number (36) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 391643997696, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (700746816000).

391643997696 is an abundant number, since it is smaller than the sum of its proper divisors (1009849634304).

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

391643997696 is a wasteful number, since it uses less digits than its factorization.

391643997696 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1099 (or 1077 counting only the distinct ones).

The product of its digits is 357128352, while the sum is 72.

The spelling of 391643997696 in words is "three hundred ninety-one billion, six hundred forty-three million, nine hundred ninety-seven thousand, six hundred ninety-six".