687404749 has 4 divisors (see below), whose sum is σ = 717291936. Its totient is φ = 657517564.

The previous prime is 687404737. The next prime is 687404771. The reversal of 687404749 is 947404786.

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.

It is a cyclic number.

It is not a de Polignac number, because 687404749 - 2⁵ = 687404717 is a prime.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (687404789) 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, 14943559 + ... + 14943604.

It is an arithmetic number, because the mean of its divisors is an integer number (179322984).

Almost surely, 2^687404749 is an apocalyptic number.

It is an amenable number.

687404749 is a deficient number, since it is larger than the sum of its proper divisors (29887187).

687404749 is a wasteful number, since it uses less digits than its factorization.

687404749 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29887186.

The product of its (nonzero) digits is 1354752, while the sum is 49.

The square root of 687404749 is about 26218.4047760347. The cubic root of 687404749 is about 882.5463220448.

The spelling of 687404749 in words is "six hundred eighty-seven million, four hundred four thousand, seven hundred forty-nine".