28181614644 has 36 divisors (see below), whose sum is σ = 74986169440. Its totient is φ = 8899457040.

The previous prime is 28181614613. The next prime is 28181614661. The reversal of 28181614644 is 44641618182.

28181614644 is a `hidden beast` number, since 2 + 8 + 181 + 6 + 1 + 464 + 4 = 666.

It is a tau number, because it is divible by the number of its divisors (36).

It is a self number, because there is not a number n which added to its sum of digits gives 28181614644.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 20599912 + ... + 20601279.

Almost surely, 2^28181614644 is an apocalyptic number.

It is an amenable number.

28181614644 is an abundant number, since it is smaller than the sum of its proper divisors (46804554796).

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

28181614644 is a wasteful number, since it uses less digits than its factorization.

28181614644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41201220 (or 41201215 counting only the distinct ones).

The product of its digits is 294912, while the sum is 45.

The spelling of 28181614644 in words is "twenty-eight billion, one hundred eighty-one million, six hundred fourteen thousand, six hundred forty-four".