686521481 has 4 divisors (see below), whose sum is σ = 687955200. Its totient is φ = 685087764.

The previous prime is 686521439. The next prime is 686521501. The reversal of 686521481 is 184125686.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 686521481 - 2¹⁸ = 686259337 is a prime.

It is a super-2 number, since 2×686521481² = 942623487748866722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (686521981) 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, 716141 + ... + 717098.

It is an arithmetic number, because the mean of its divisors is an integer number (171988800).

Almost surely, 2^686521481 is an apocalyptic number.

It is an amenable number.

686521481 is a deficient number, since it is larger than the sum of its proper divisors (1433719).

686521481 is a wasteful number, since it uses less digits than its factorization.

686521481 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1433718.

The product of its digits is 92160, while the sum is 41.

The square root of 686521481 is about 26201.5549347744. The cubic root of 686521481 is about 882.1681561762.

The spelling of 686521481 in words is "six hundred eighty-six million, five hundred twenty-one thousand, four hundred eighty-one".