687680045 has 32 divisors (see below), whose sum is σ = 929063520. Its totient is φ = 485130240.

The previous prime is 687680033. The next prime is 687680047. The reversal of 687680045 is 540086786.

It can be written as a sum of positive squares in 16 ways, for example, as 285035689 + 402644356 = 16883^2 + 20066^2 .

It is not a de Polignac number, because 687680045 - 2²² = 683485741 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 687679978 and 687680005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (687680047) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 180965 + ... + 184725.

It is an arithmetic number, because the mean of its divisors is an integer number (29033235).

Almost surely, 2^687680045 is an apocalyptic number.

687680045 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

It is an amenable number.

687680045 is a deficient number, since it is larger than the sum of its proper divisors (241383475).

687680045 is a wasteful number, since it uses less digits than its factorization.

687680045 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3905.

The product of its (nonzero) digits is 322560, while the sum is 44.

The square root of 687680045 is about 26223.6543029380. The cubic root of 687680045 is about 882.6641221452.

The spelling of 687680045 in words is "six hundred eighty-seven million, six hundred eighty thousand, forty-five".