681291777 has 4 divisors (see below), whose sum is σ = 908389040. Its totient is φ = 454194516.

The previous prime is 681291773. The next prime is 681291799. The reversal of 681291777 is 777192186.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 681291777 - 2² = 681291773 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (681291773) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 113548627 + ... + 113548632.

It is an arithmetic number, because the mean of its divisors is an integer number (227097260).

Almost surely, 2^681291777 is an apocalyptic number.

It is an amenable number.

681291777 is a deficient number, since it is larger than the sum of its proper divisors (227097263).

681291777 is a wasteful number, since it uses less digits than its factorization.

681291777 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 227097262.

The product of its digits is 296352, while the sum is 48.

The square root of 681291777 is about 26101.5665621817. The cubic root of 681291777 is about 879.9224178333.

It can be divided in two parts, 6812 and 91777, that added together give a palindrome (98589).

The spelling of 681291777 in words is "six hundred eighty-one million, two hundred ninety-one thousand, seven hundred seventy-seven".