681249751 has 8 divisors (see below), whose sum is σ = 838461344. Its totient is φ = 539010720.

The previous prime is 681249743. The next prime is 681249761. The reversal of 681249751 is 157942186.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 681249751 - 2³ = 681249743 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 681249698 and 681249707.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (681249761) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3743040 + ... + 3743221.

It is an arithmetic number, because the mean of its divisors is an integer number (104807668).

Almost surely, 2^681249751 is an apocalyptic number.

681249751 is a deficient number, since it is larger than the sum of its proper divisors (157211593).

681249751 is a wasteful number, since it uses less digits than its factorization.

681249751 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7486281.

The product of its digits is 120960, while the sum is 43.

The square root of 681249751 is about 26100.7615023010. The cubic root of 681249751 is about 879.9043245674.

The spelling of 681249751 in words is "six hundred eighty-one million, two hundred forty-nine thousand, seven hundred fifty-one".