680235120781 has 4 divisors (see below), whose sum is σ = 681750121500. Its totient is φ = 678720120064.

The previous prime is 680235120689. The next prime is 680235120791. The reversal of 680235120781 is 187021532086.

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 360280854756 + 319954266025 = 600234^2 + 565645^2 .

It is a cyclic number.

It is not a de Polignac number, because 680235120781 - 2⁹ = 680235120269 is a prime.

It is a super-2 number, since 2×680235120781² (a number of 24 digits) 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 (680235120791) 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, 757499686 + ... + 757500583.

It is an arithmetic number, because the mean of its divisors is an integer number (170437530375).

Almost surely, 2^680235120781 is an apocalyptic number.

It is an amenable number.

680235120781 is a deficient number, since it is larger than the sum of its proper divisors (1515000719).

680235120781 is a wasteful number, since it uses less digits than its factorization.

680235120781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1515000718.

The product of its (nonzero) digits is 161280, while the sum is 43.

The spelling of 680235120781 in words is "six hundred eighty billion, two hundred thirty-five million, one hundred twenty thousand, seven hundred eighty-one".