681145920 has 672 divisors, whose sum is σ = 3035515392. Its totient is φ = 136249344.

The previous prime is 681145903. The next prime is 681145921. The reversal of 681145920 is 29541186.

681145920 is a `hidden beast` number, since 68 + 1 + 1 + 4 + 592 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (672).

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 (681145921) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 6027784 + ... + 6027896.

It is an arithmetic number, because the mean of its divisors is an integer number (4517136).

Almost surely, 2^681145920 is an apocalyptic number.

681145920 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 681145920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1517757696).

681145920 is an abundant number, since it is smaller than the sum of its proper divisors (2354369472).

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

681145920 is a wasteful number, since it uses less digits than its factorization.

681145920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 179 (or 166 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 36.

The square root of 681145920 is about 26098.7723849226. The cubic root of 681145920 is about 879.8596194805.

The spelling of 681145920 in words is "six hundred eighty-one million, one hundred forty-five thousand, nine hundred twenty".