681990320 has 160 divisors (see below), whose sum is σ = 1803098880. Its totient is φ = 237726720.

The previous prime is 681990311. The next prime is 681990329. The reversal of 681990320 is 23099186.

It is an interprime number because it is at equal distance from previous prime (681990311) and next prime (681990329).

It is a super-2 number, since 2×681990320² = 930221593147404800, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (681990329) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2535146 + ... + 2535414.

It is an arithmetic number, because the mean of its divisors is an integer number (11269368).

Almost surely, 2^681990320 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 681990320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (901549440).

681990320 is an abundant number, since it is smaller than the sum of its proper divisors (1121108560).

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

681990320 is a wasteful number, since it uses less digits than its factorization.

681990320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 403 (or 397 counting only the distinct ones).

The product of its (nonzero) digits is 23328, while the sum is 38.

The square root of 681990320 is about 26114.9443805649. The cubic root of 681990320 is about 880.2230495205.

The spelling of 681990320 in words is "six hundred eighty-one million, nine hundred ninety thousand, three hundred twenty".