686741215 has 4 divisors (see below), whose sum is σ = 824089464. Its totient is φ = 549392968.

The previous prime is 686741213. The next prime is 686741219. The reversal of 686741215 is 512147686.

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

It is a cyclic number.

It is not a de Polignac number, because 686741215 - 2¹ = 686741213 is a prime.

It is a super-2 number, since 2×686741215² = 943226992759352450, which contains 22 as substring.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (686741213) 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, 68674117 + ... + 68674126.

It is an arithmetic number, because the mean of its divisors is an integer number (206022366).

Almost surely, 2^686741215 is an apocalyptic number.

686741215 is a deficient number, since it is larger than the sum of its proper divisors (137348249).

686741215 is a wasteful number, since it uses less digits than its factorization.

686741215 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 137348248.

The product of its digits is 80640, while the sum is 40.

The square root of 686741215 is about 26205.7477473931. The cubic root of 686741215 is about 882.2622642586.

The spelling of 686741215 in words is "six hundred eighty-six million, seven hundred forty-one thousand, two hundred fifteen".