687242537 has 4 divisors (see below), whose sum is σ = 691620036. Its totient is φ = 682865040.

The previous prime is 687242509. The next prime is 687242539. The reversal of 687242537 is 735242786.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 735242786 = 2 ⋅367621393.

It can be written as a sum of positive squares in 2 ways, for example, as 88755241 + 598487296 = 9421^2 + 24464^2 .

It is a cyclic number.

It is not a de Polignac number, because 687242537 - 2⁶ = 687242473 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (687242539) 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 3 ways as a sum of consecutive naturals, for example, 2188514 + ... + 2188827.

It is an arithmetic number, because the mean of its divisors is an integer number (172905009).

Almost surely, 2^687242537 is an apocalyptic number.

It is an amenable number.

687242537 is a deficient number, since it is larger than the sum of its proper divisors (4377499).

687242537 is a wasteful number, since it uses less digits than its factorization.

687242537 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4377498.

The product of its digits is 564480, while the sum is 44.

The square root of 687242537 is about 26215.3111177419. The cubic root of 687242537 is about 882.4768962485.

The spelling of 687242537 in words is "six hundred eighty-seven million, two hundred forty-two thousand, five hundred thirty-seven".