679750781 has 4 divisors (see below), whose sum is σ = 680101500. Its totient is φ = 679400064.

The previous prime is 679750769. The next prime is 679750787. The reversal of 679750781 is 187057976.

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 611770756 + 67980025 = 24734^2 + 8245^2 .

It is a cyclic number.

It is not a de Polignac number, because 679750781 - 2¹⁸ = 679488637 is a prime.

It is a super-2 number, since 2×679750781² = 924122248540219922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (679750787) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 172436 + ... + 176333.

It is an arithmetic number, because the mean of its divisors is an integer number (170025375).

Almost surely, 2^679750781 is an apocalyptic number.

It is an amenable number.

679750781 is a deficient number, since it is larger than the sum of its proper divisors (350719).

679750781 is a wasteful number, since it uses less digits than its factorization.

679750781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 350718.

The product of its (nonzero) digits is 740880, while the sum is 50.

The square root of 679750781 is about 26072.0306267080. The cubic root of 679750781 is about 879.2584925309.

The spelling of 679750781 in words is "six hundred seventy-nine million, seven hundred fifty thousand, seven hundred eighty-one".