28620810640 has 20 divisors (see below), whose sum is σ = 66543384924. Its totient is φ = 11448324224.

The previous prime is 28620810623. The next prime is 28620810641. The reversal of 28620810640 is 4601802682.

It can be written as a sum of positive squares in 2 ways, for example, as 22600912896 + 6019897744 = 150336^2 + 77588^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a self number, because there is not a number n which added to its sum of digits gives 28620810640.

It is not an unprimeable number, because it can be changed into a prime (28620810641) 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, 178879987 + ... + 178880146.

Almost surely, 2^28620810640 is an apocalyptic number.

28620810640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28620810640 is an abundant number, since it is smaller than the sum of its proper divisors (37922574284).

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

28620810640 is a wasteful number, since it uses less digits than its factorization.

28620810640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 357760146 (or 357760140 counting only the distinct ones).

The product of its (nonzero) digits is 36864, while the sum is 37.

It can be divided in two parts, 286 and 20810640, that added together give a triangular number (20810926 = T₆₄₅₁).

The spelling of 28620810640 in words is "twenty-eight billion, six hundred twenty million, eight hundred ten thousand, six hundred forty".