681621732 has 216 divisors, whose sum is σ = 2124027360. Its totient is φ = 181647360.

The previous prime is 681621727. The next prime is 681621737. The reversal of 681621732 is 237126186.

It is an interprime number because it is at equal distance from previous prime (681621727) and next prime (681621737).

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

It is not an unprimeable number, because it can be changed into a prime (681621737) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 9337248 + ... + 9337320.

It is an arithmetic number, because the mean of its divisors is an integer number (9833460).

Almost surely, 2^681621732 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 681621732, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1062013680).

681621732 is an abundant number, since it is smaller than the sum of its proper divisors (1442405628).

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

681621732 is a wasteful number, since it uses less digits than its factorization.

681621732 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 203 (or 125 counting only the distinct ones).

The product of its digits is 24192, while the sum is 36.

The square root of 681621732 is about 26107.8863947276. The cubic root of 681621732 is about 880.0644460378.

The spelling of 681621732 in words is "six hundred eighty-one million, six hundred twenty-one thousand, seven hundred thirty-two".