687248491 has 4 divisors (see below), whose sum is σ = 687309184. Its totient is φ = 687187800.

The previous prime is 687248479. The next prime is 687248521. The reversal of 687248491 is 194842786.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 194842786 = 2 ⋅97421393.

It is a cyclic number.

It is not a de Polignac number, because 687248491 - 2⁵ = 687248459 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (687248431) 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, 7755 + ... + 37876.

It is an arithmetic number, because the mean of its divisors is an integer number (171827296).

Almost surely, 2^687248491 is an apocalyptic number.

687248491 is a deficient number, since it is larger than the sum of its proper divisors (60693).

687248491 is a wasteful number, since it uses less digits than its factorization.

687248491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60692.

The product of its digits is 774144, while the sum is 49.

The square root of 687248491 is about 26215.4246770866. The cubic root of 687248491 is about 882.4794447191.

The spelling of 687248491 in words is "six hundred eighty-seven million, two hundred forty-eight thousand, four hundred ninety-one".