681647652 has 72 divisors (see below), whose sum is σ = 1974068096. Its totient is φ = 194275584.

The previous prime is 681647651. The next prime is 681647663. The reversal of 681647652 is 256746186.

It is a super-2 number, since 2×681647652² = 929287042954226208, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 681647598 and 681647607.

It is not an unprimeable number, because it can be changed into a prime (681647651) by changing a digit.

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 23 ways as a sum of consecutive naturals, for example, 105993 + ... + 112239.

Almost surely, 2^681647652 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 681647652, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (987034048).

681647652 is an abundant number, since it is smaller than the sum of its proper divisors (1292420444).

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

681647652 is a wasteful number, since it uses less digits than its factorization.

681647652 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6697 (or 6692 counting only the distinct ones).

The product of its digits is 483840, while the sum is 45.

The square root of 681647652 is about 26108.3827917395. The cubic root of 681647652 is about 880.0756012872.

The spelling of 681647652 in words is "six hundred eighty-one million, six hundred forty-seven thousand, six hundred fifty-two".