688581494 has 4 divisors (see below), whose sum is σ = 1032872244. Its totient is φ = 344290746.

The previous prime is 688581473. The next prime is 688581497. The reversal of 688581494 is 494185886.

It is a happy number.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (688581497) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 172145372 + ... + 172145375.

It is an arithmetic number, because the mean of its divisors is an integer number (258218061).

Almost surely, 2^688581494 is an apocalyptic number.

688581494 is a deficient number, since it is larger than the sum of its proper divisors (344290750).

688581494 is a wasteful number, since it uses less digits than its factorization.

688581494 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 344290749.

The product of its digits is 2211840, while the sum is 53.

The square root of 688581494 is about 26240.8363814875. The cubic root of 688581494 is about 883.0496353775.

The spelling of 688581494 in words is "six hundred eighty-eight million, five hundred eighty-one thousand, four hundred ninety-four".