687297949 has 4 divisors (see below), whose sum is σ = 740167036. Its totient is φ = 634428864.

The previous prime is 687297899. The next prime is 687297953. The reversal of 687297949 is 949792786.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 163712025 + 523585924 = 12795^2 + 22882^2 .

It is a cyclic number.

It is not a de Polignac number, because 687297949 - 2¹¹ = 687295901 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 (687297449) 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, 26434524 + ... + 26434549.

It is an arithmetic number, because the mean of its divisors is an integer number (185041759).

Almost surely, 2^687297949 is an apocalyptic number.

It is an amenable number.

687297949 is a deficient number, since it is larger than the sum of its proper divisors (52869087).

687297949 is a wasteful number, since it uses less digits than its factorization.

687297949 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52869086.

The product of its digits is 13716864, while the sum is 61.

The square root of 687297949 is about 26216.3679597308. The cubic root of 687297949 is about 882.5006134919.

The spelling of 687297949 in words is "six hundred eighty-seven million, two hundred ninety-seven thousand, nine hundred forty-nine".