681505020 has 72 divisors (see below), whose sum is σ = 2362555104. Its totient is φ = 155772288.

The previous prime is 681505009. The next prime is 681505021. The reversal of 681505020 is 20505186.

681505020 is a `hidden beast` number, since 6 + 8 + 150 + 502 + 0 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (681505021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 269179 + ... + 271698.

Almost surely, 2^681505020 is an apocalyptic number.

681505020 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

681505020 is an abundant number, since it is smaller than the sum of its proper divisors (1681050084).

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

681505020 is a wasteful number, since it uses less digits than its factorization.

681505020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 540899 (or 540894 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 27.

The square root of 681505020 is about 26105.6511123550. The cubic root of 681505020 is about 880.0142129247.

The spelling of 681505020 in words is "six hundred eighty-one million, five hundred five thousand, twenty".