681813951 has 64 divisors (see below), whose sum is σ = 1196633088. Its totient is φ = 335075328.

The previous prime is 681813931. The next prime is 681813953. The reversal of 681813951 is 159318186.

It is not a de Polignac number, because 681813951 - 2¹⁰ = 681812927 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (681813953) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 495901 + ... + 497273.

It is an arithmetic number, because the mean of its divisors is an integer number (18697392).

Almost surely, 2^681813951 is an apocalyptic number.

681813951 is a deficient number, since it is larger than the sum of its proper divisors (514819137).

681813951 is a wasteful number, since it uses less digits than its factorization.

681813951 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1520.

The product of its digits is 51840, while the sum is 42.

The square root of 681813951 is about 26111.5673792287. The cubic root of 681813951 is about 880.1471650400.

The spelling of 681813951 in words is "six hundred eighty-one million, eight hundred thirteen thousand, nine hundred fifty-one".