688999841 has 4 divisors (see below), whose sum is σ = 701999892. Its totient is φ = 675999792.

The previous prime is 688999813. The next prime is 688999853. The reversal of 688999841 is 148999886.

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 236544400 + 452455441 = 15380^2 + 21271^2 .

It is a cyclic number.

It is not a de Polignac number, because 688999841 - 2²⁶ = 621890977 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (688999811) 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, 6499946 + ... + 6500051.

It is an arithmetic number, because the mean of its divisors is an integer number (175499973).

Almost surely, 2^688999841 is an apocalyptic number.

It is an amenable number.

688999841 is a deficient number, since it is larger than the sum of its proper divisors (13000051).

688999841 is a wasteful number, since it uses less digits than its factorization.

688999841 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13000050.

The product of its digits is 8957952, while the sum is 62.

The square root of 688999841 is about 26248.8064681044. The cubic root of 688999841 is about 883.2284311485.

The spelling of 688999841 in words is "six hundred eighty-eight million, nine hundred ninety-nine thousand, eight hundred forty-one".