391596668546 has 4 divisors (see below), whose sum is σ = 587395002822. Its totient is φ = 195798334272.

The previous prime is 391596668483. The next prime is 391596668549. The reversal of 391596668546 is 645866695193.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 645866695193 = 139 ⋅4646522987.

It can be written as a sum of positive squares in only one way, i.e., 383253855625 + 8342812921 = 619075^2 + 91339^2 .

It is not an unprimeable number, because it can be changed into a prime (391596668549) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 97899167135 + ... + 97899167138.

Almost surely, 2^391596668546 is an apocalyptic number.

391596668546 is a deficient number, since it is larger than the sum of its proper divisors (195798334276).

391596668546 is a wasteful number, since it uses less digits than its factorization.

391596668546 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 195798334275.

The product of its digits is 251942400, while the sum is 68.

The spelling of 391596668546 in words is "three hundred ninety-one billion, five hundred ninety-six million, six hundred sixty-eight thousand, five hundred forty-six".