686944250041 has 27 divisors (see below), whose sum is σ = 805047553359. Its totient is φ = 584458046928.

The previous prime is 686944250033. The next prime is 686944250063. The reversal of 686944250041 is 140052449686.

The square root of 686944250041 is 828821.

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

It can be written as a sum of positive squares in only one way, i.e., 91670278441 + 595273971600 = 302771^2 + 771540^2 .

It is not a de Polignac number, because 686944250041 - 2³ = 686944250033 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (49).

It is not an unprimeable number, because it can be changed into a prime (686944250021) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 968891395 + ... + 968892103.

Almost surely, 2^686944250041 is an apocalyptic number.

686944250041 is the 828821-st square number.

686944250041 is the 414411-st centered octagonal number.

It is an amenable number.

686944250041 is a deficient number, since it is larger than the sum of its proper divisors (118103303318).

686944250041 is an frugal number, since it uses more digits than its factorization.

686944250041 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1766 (or 883 counting only the distinct ones).

The product of its (nonzero) digits is 1658880, while the sum is 49.

Multiplying 686944250041 by its sum of digits (49), we get a square (33660268252009 = 5801747²).

686944250041 divided by its sum of digits (49) gives a square (14019270409 = 118403²).

The spelling of 686944250041 in words is "six hundred eighty-six billion, nine hundred forty-four million, two hundred fifty thousand, forty-one".