687135492 has 18 divisors (see below), whose sum is σ = 1736925918. Its totient is φ = 229045152.

The previous prime is 687135467. The next prime is 687135497. The reversal of 687135492 is 294531786.

687135492 is a `hidden beast` number, since 68 + 71 + 35 + 492 = 666.

It can be written as a sum of positive squares in only one way, i.e., 590781636 + 96353856 = 24306^2 + 9816^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is not an unprimeable number, because it can be changed into a prime (687135497) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 9543513 + ... + 9543584.

Almost surely, 2^687135492 is an apocalyptic number.

It is an amenable number.

687135492 is an abundant number, since it is smaller than the sum of its proper divisors (1049790426).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

687135492 is a wasteful number, since it uses less digits than its factorization.

687135492 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19087107 (or 19087102 counting only the distinct ones).

The product of its digits is 362880, while the sum is 45.

The square root of 687135492 is about 26213.2693878501. The cubic root of 687135492 is about 882.4310756251.

The spelling of 687135492 in words is "six hundred eighty-seven million, one hundred thirty-five thousand, four hundred ninety-two".