688990393 has 8 divisors (see below), whose sum is σ = 847988288. Its totient is φ = 545135184.

The previous prime is 688990339. The next prime is 688990403. The reversal of 688990393 is 393099886.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 688990393 - 2¹⁷ = 688859321 is a prime.

It is not an unprimeable number, because it can be changed into a prime (688990193) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3785571 + ... + 3785752.

It is an arithmetic number, because the mean of its divisors is an integer number (105998536).

Almost surely, 2^688990393 is an apocalyptic number.

It is an amenable number.

688990393 is a deficient number, since it is larger than the sum of its proper divisors (158997895).

688990393 is a wasteful number, since it uses less digits than its factorization.

688990393 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7571343.

The product of its (nonzero) digits is 2519424, while the sum is 55.

The square root of 688990393 is about 26248.6264973998. The cubic root of 688990393 is about 883.2243940017.

The spelling of 688990393 in words is "six hundred eighty-eight million, nine hundred ninety thousand, three hundred ninety-three".