686247761 has 8 divisors (see below), whose sum is σ = 695138760. Its totient is φ = 677383168.

The previous prime is 686247739. The next prime is 686247787. The reversal of 686247761 is 167742686.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 2739025 + 683508736 = 1655^2 + 26144^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-686247761 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (686244761) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 48665 + ... + 61161.

It is an arithmetic number, because the mean of its divisors is an integer number (86892345).

Almost surely, 2^686247761 is an apocalyptic number.

It is an amenable number.

686247761 is a deficient number, since it is larger than the sum of its proper divisors (8890999).

686247761 is a wasteful number, since it uses less digits than its factorization.

686247761 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13203.

The product of its digits is 677376, while the sum is 47.

The square root of 686247761 is about 26196.3310599023. The cubic root of 686247761 is about 882.0508987788.

The spelling of 686247761 in words is "six hundred eighty-six million, two hundred forty-seven thousand, seven hundred sixty-one".