681535512 has 128 divisors (see below), whose sum is σ = 2208000000. Its totient is φ = 194703264.

The previous prime is 681535511. The next prime is 681535541. The reversal of 681535512 is 215535186.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (681535511) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 69489 + ... + 78687.

It is an arithmetic number, because the mean of its divisors is an integer number (17250000).

Almost surely, 2^681535512 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 681535512, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1104000000).

681535512 is an abundant number, since it is smaller than the sum of its proper divisors (1526464488).

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

681535512 is a wasteful number, since it uses less digits than its factorization.

681535512 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9235 (or 9211 counting only the distinct ones).

The product of its digits is 36000, while the sum is 36.

The square root of 681535512 is about 26106.2351173048. The cubic root of 681535512 is about 880.0273373050.

The spelling of 681535512 in words is "six hundred eighty-one million, five hundred thirty-five thousand, five hundred twelve".