686122049 has 4 divisors (see below), whose sum is σ = 709781460. Its totient is φ = 662462640.

The previous prime is 686122007. The next prime is 686122051. The reversal of 686122049 is 940221686.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 510082225 + 176039824 = 22585^2 + 13268^2 .

It is a cyclic number.

It is not a de Polignac number, because 686122049 - 2¹² = 686117953 is a prime.

It is a super-2 number, since 2×686122049² = 941526932247916802, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (686122649) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11829662 + ... + 11829719.

It is an arithmetic number, because the mean of its divisors is an integer number (177445365).

Almost surely, 2^686122049 is an apocalyptic number.

It is an amenable number.

686122049 is a deficient number, since it is larger than the sum of its proper divisors (23659411).

686122049 is a wasteful number, since it uses less digits than its factorization.

686122049 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23659410.

The product of its (nonzero) digits is 41472, while the sum is 38.

The square root of 686122049 is about 26193.9315300319. The cubic root of 686122049 is about 881.9970352617.

The spelling of 686122049 in words is "six hundred eighty-six million, one hundred twenty-two thousand, forty-nine".