688772831 has 4 divisors (see below), whose sum is σ = 688844112. Its totient is φ = 688701552.

The previous prime is 688772807. The next prime is 688772837. The reversal of 688772831 is 138277886.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 688772831 - 2⁶ = 688772767 is a prime.

It is a super-2 number, since 2×688772831² = 948816025447509122, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 688772831.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (688772837) 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, 18350 + ... + 41403.

It is an arithmetic number, because the mean of its divisors is an integer number (172211028).

Almost surely, 2^688772831 is an apocalyptic number.

688772831 is a deficient number, since it is larger than the sum of its proper divisors (71281).

688772831 is a wasteful number, since it uses less digits than its factorization.

688772831 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71280.

The product of its digits is 903168, while the sum is 50.

The square root of 688772831 is about 26244.4819152522. The cubic root of 688772831 is about 883.1314191713.

The spelling of 688772831 in words is "six hundred eighty-eight million, seven hundred seventy-two thousand, eight hundred thirty-one".