391961560085 has 16 divisors (see below), whose sum is σ = 487823871600. Its totient is φ = 301978177536.

The previous prime is 391961560043. The next prime is 391961560099. The reversal of 391961560085 is 580065169193.

It can be written as a sum of positive squares in 8 ways, for example, as 6858158596 + 385103401489 = 82814^2 + 620567^2 .

It is a cyclic number.

It is not a de Polignac number, because 391961560085 - 2²² = 391957365781 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3418124 + ... + 3530933.

It is an arithmetic number, because the mean of its divisors is an integer number (30488991975).

Almost surely, 2^391961560085 is an apocalyptic number.

It is an amenable number.

391961560085 is a deficient number, since it is larger than the sum of its proper divisors (95862311515).

391961560085 is a wasteful number, since it uses less digits than its factorization.

391961560085 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6949480.

The product of its (nonzero) digits is 1749600, while the sum is 53.

The spelling of 391961560085 in words is "three hundred ninety-one billion, nine hundred sixty-one million, five hundred sixty thousand, eighty-five".