391342658681 has 32 divisors (see below), whose sum is σ = 465810998688. Its totient is φ = 325377699840.

The previous prime is 391342658543. The next prime is 391342658683. The reversal of 391342658681 is 186856243193.

It can be written as a sum of positive squares in 16 ways, for example, as 24814125625 + 366528533056 = 157525^2 + 605416^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-391342658681 is a prime.

It is a super-2 number, since 2×391342658681² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (391342658683) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 106511 + ... + 891083.

It is an arithmetic number, because the mean of its divisors is an integer number (14556593709).

Almost surely, 2^391342658681 is an apocalyptic number.

It is an amenable number.

391342658681 is a deficient number, since it is larger than the sum of its proper divisors (74468340007).

391342658681 is a wasteful number, since it uses less digits than its factorization.

391342658681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 784701.

The product of its digits is 7464960, while the sum is 56.

The spelling of 391342658681 in words is "three hundred ninety-one billion, three hundred forty-two million, six hundred fifty-eight thousand, six hundred eighty-one".