20851587604 has 12 divisors (see below), whose sum is σ = 36614820564. Its totient is φ = 10390210304.

The previous prime is 20851587599. The next prime is 20851587607. The reversal of 20851587604 is 40678515802.

It can be written as a sum of positive squares in 2 ways, for example, as 18495456004 + 2356131600 = 135998^2 + 48540^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20851587607) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8894557 + ... + 8896900.

It is an arithmetic number, because the mean of its divisors is an integer number (3051235047).

Almost surely, 2^20851587604 is an apocalyptic number.

It is an amenable number.

20851587604 is a deficient number, since it is larger than the sum of its proper divisors (15763232960).

20851587604 is a wasteful number, since it uses less digits than its factorization.

20851587604 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17791754 (or 17791752 counting only the distinct ones).

The product of its (nonzero) digits is 537600, while the sum is 46.

The spelling of 20851587604 in words is "twenty billion, eight hundred fifty-one million, five hundred eighty-seven thousand, six hundred four".