687133391 has 8 divisors (see below), whose sum is σ = 804449184. Its totient is φ = 574606080.

The previous prime is 687133367. The next prime is 687133409. The reversal of 687133391 is 193331786.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-687133391 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (41).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (687133351) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1196810 + ... + 1197383.

It is an arithmetic number, because the mean of its divisors is an integer number (100556148).

Almost surely, 2^687133391 is an apocalyptic number.

687133391 is a deficient number, since it is larger than the sum of its proper divisors (117315793).

687133391 is a wasteful number, since it uses less digits than its factorization.

687133391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2394241.

The product of its digits is 81648, while the sum is 41.

The square root of 687133391 is about 26213.2293126963. The cubic root of 687133391 is about 882.4301762442.

The spelling of 687133391 in words is "six hundred eighty-seven million, one hundred thirty-three thousand, three hundred ninety-one".