681051564 has 60 divisors (see below), whose sum is σ = 1783978504. Its totient is φ = 226561536.

The previous prime is 681051541. The next prime is 681051593. The reversal of 681051564 is 465150186.

681051564 is a `hidden beast` number, since 6 + 81 + 0 + 515 + 64 = 666.

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

It is an unprimeable number.

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 19 ways as a sum of consecutive naturals, for example, 185127 + ... + 188769.

Almost surely, 2^681051564 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 681051564, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (891989252).

681051564 is an abundant number, since it is smaller than the sum of its proper divisors (1102926940).

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

681051564 is a wasteful number, since it uses less digits than its factorization.

681051564 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4236 (or 4225 counting only the distinct ones).

The product of its (nonzero) digits is 28800, while the sum is 36.

The square root of 681051564 is about 26096.9646510854. The cubic root of 681051564 is about 879.8189899739.

The spelling of 681051564 in words is "six hundred eighty-one million, fifty-one thousand, five hundred sixty-four".