687071405 has 16 divisors (see below), whose sum is σ = 874560240. Its totient is φ = 516390912.

The previous prime is 687071381. The next prime is 687071419. The reversal of 687071405 is 504170786.

It can be written as a sum of positive squares in 8 ways, for example, as 207417604 + 479653801 = 14402^2 + 21901^2 .

It is not a de Polignac number, because 687071405 - 2²² = 682877101 is a prime.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 42041 + ... + 56049.

It is an arithmetic number, because the mean of its divisors is an integer number (54660015).

Almost surely, 2^687071405 is an apocalyptic number.

It is an amenable number.

687071405 is a deficient number, since it is larger than the sum of its proper divisors (187488835).

687071405 is a wasteful number, since it uses less digits than its factorization.

687071405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14608.

The product of its (nonzero) digits is 47040, while the sum is 38.

The square root of 687071405 is about 26212.0469441057. The cubic root of 687071405 is about 882.4036409007.

The spelling of 687071405 in words is "six hundred eighty-seven million, seventy-one thousand, four hundred five".