391621706459 has 4 divisors (see below), whose sum is σ = 412233375240. Its totient is φ = 371010037680.

The previous prime is 391621706447. The next prime is 391621706519. The reversal of 391621706459 is 954607126193.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 391621706459 - 2¹² = 391621702363 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 391621706459.

It is not an unprimeable number, because it can be changed into a prime (391621706159) 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, 10305834362 + ... + 10305834399.

It is an arithmetic number, because the mean of its divisors is an integer number (103058343810).

Almost surely, 2^391621706459 is an apocalyptic number.

391621706459 is a deficient number, since it is larger than the sum of its proper divisors (20611668781).

391621706459 is a wasteful number, since it uses less digits than its factorization.

391621706459 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20611668780.

The product of its (nonzero) digits is 2449440, while the sum is 53.

The spelling of 391621706459 in words is "three hundred ninety-one billion, six hundred twenty-one million, seven hundred six thousand, four hundred fifty-nine".