681548551 has 16 divisors (see below), whose sum is σ = 707414400. Its totient is φ = 656252928.

The previous prime is 681548519. The next prime is 681548557. The reversal of 681548551 is 155845186.

It is a cyclic number.

It is not a de Polignac number, because 681548551 - 2⁵ = 681548519 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 681548498 and 681548507.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (681548557) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 885895 + ... + 886663.

It is an arithmetic number, because the mean of its divisors is an integer number (44213400).

Almost surely, 2^681548551 is an apocalyptic number.

681548551 is a deficient number, since it is larger than the sum of its proper divisors (25865849).

681548551 is a wasteful number, since it uses less digits than its factorization.

681548551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1098.

The product of its digits is 192000, while the sum is 43.

The square root of 681548551 is about 26106.4848457237. The cubic root of 681548551 is about 880.0329494378.

The spelling of 681548551 in words is "six hundred eighty-one million, five hundred forty-eight thousand, five hundred fifty-one".