391661937241 has 9 divisors (see below), whose sum is σ = 397146990909. Its totient is φ = 386251645536.

The previous prime is 391661937193. The next prime is 391661937253. The reversal of 391661937241 is 142739166193.

The square root of 391661937241 is 625829.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 4952077641 + 386709859600 = 70371^2 + 621860^2 .

It is not a de Polignac number, because 391661937241 - 2¹³ = 391661929049 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (391661937341) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 45681231 + ... + 45689803.

Almost surely, 2^391661937241 is an apocalyptic number.

391661937241 is the 625829-th square number.

391661937241 is the 312915-th centered octagonal number.

It is an amenable number.

391661937241 is a deficient number, since it is larger than the sum of its proper divisors (5485053668).

391661937241 is an frugal number, since it uses more digits than its factorization.

391661937241 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17292 (or 8646 counting only the distinct ones).

The product of its digits is 1469664, while the sum is 52.

The spelling of 391661937241 in words is "three hundred ninety-one billion, six hundred sixty-one million, nine hundred thirty-seven thousand, two hundred forty-one".