687488891 has 16 divisors (see below), whose sum is σ = 754668288. Its totient is φ = 623462400.

The previous prime is 687488869. The next prime is 687488899. The reversal of 687488891 is 198884786.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-687488891 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 687488891.

It is not an unprimeable number, because it can be changed into a prime (687488899) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 124301 + ... + 129713.

It is an arithmetic number, because the mean of its divisors is an integer number (47166768).

Almost surely, 2^687488891 is an apocalyptic number.

687488891 is a deficient number, since it is larger than the sum of its proper divisors (67179397).

687488891 is a wasteful number, since it uses less digits than its factorization.

687488891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5702.

The product of its digits is 6193152, while the sum is 59.

The square root of 687488891 is about 26220.0093630799. The cubic root of 687488891 is about 882.5823300314.

The spelling of 687488891 in words is "six hundred eighty-seven million, four hundred eighty-eight thousand, eight hundred ninety-one".