687634253 has 4 divisors (see below), whose sum is σ = 687702720. Its totient is φ = 687565788.

The previous prime is 687634229. The next prime is 687634271. The reversal of 687634253 is 352436786.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 687634253 - 2²⁰ = 686585677 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (687634223) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15893 + ... + 40346.

It is an arithmetic number, because the mean of its divisors is an integer number (171925680).

Almost surely, 2^687634253 is an apocalyptic number.

It is an amenable number.

687634253 is a deficient number, since it is larger than the sum of its proper divisors (68467).

687634253 is a wasteful number, since it uses less digits than its factorization.

687634253 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68466.

The product of its digits is 725760, while the sum is 44.

The square root of 687634253 is about 26222.7811835434. The cubic root of 687634253 is about 882.6445297718.

The spelling of 687634253 in words is "six hundred eighty-seven million, six hundred thirty-four thousand, two hundred fifty-three".