681991232 has 28 divisors (see below), whose sum is σ = 1457430156. Its totient is φ = 314764800.

The previous prime is 681991213. The next prime is 681991243. The reversal of 681991232 is 232199186.

It can be written as a sum of positive squares in 2 ways, for example, as 453860416 + 228130816 = 21304^2 + 15104^2 .

It is a super-2 number, since 2×681991232² = 930224081049755648, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 681991232.

It is an unprimeable number.

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, 409019 + ... + 410682.

It is an arithmetic number, because the mean of its divisors is an integer number (52051077).

Almost surely, 2^681991232 is an apocalyptic number.

It is an amenable number.

681991232 is an abundant number, since it is smaller than the sum of its proper divisors (775438924).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

681991232 is a wasteful number, since it uses less digits than its factorization.

681991232 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 819726 (or 819716 counting only the distinct ones).

The product of its digits is 46656, while the sum is 41.

The square root of 681991232 is about 26114.9618418255. The cubic root of 681991232 is about 880.2234418834.

The spelling of 681991232 in words is "six hundred eighty-one million, nine hundred ninety-one thousand, two hundred thirty-two".