687640354 has 4 divisors (see below), whose sum is σ = 1031460534. Its totient is φ = 343820176.

The previous prime is 687640351. The next prime is 687640379. The reversal of 687640354 is 453046786.

687640354 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It can be written as a sum of positive squares in only one way, i.e., 631165129 + 56475225 = 25123^2 + 7515^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 687640354.

It is not an unprimeable number, because it can be changed into a prime (687640351) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 171910087 + ... + 171910090.

Almost surely, 2^687640354 is an apocalyptic number.

687640354 is a deficient number, since it is larger than the sum of its proper divisors (343820180).

687640354 is a wasteful number, since it uses less digits than its factorization.

687640354 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 343820179.

The product of its (nonzero) digits is 483840, while the sum is 43.

The square root of 687640354 is about 26222.8975134328. The cubic root of 687640354 is about 882.6471401703.

The spelling of 687640354 in words is "six hundred eighty-seven million, six hundred forty thousand, three hundred fifty-four".