28181020281 has 8 divisors (see below), whose sum is σ = 38135510304. Its totient is φ = 18506938560.

The previous prime is 28181020277. The next prime is 28181020297. The reversal of 28181020281 is 18202018182.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 28181020281 - 2² = 28181020277 is a prime.

It is a super-2 number, since 2×28181020281² (a number of 22 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (28181020081) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 70101840 + ... + 70102241.

It is an arithmetic number, because the mean of its divisors is an integer number (4766938788).

Almost surely, 2^28181020281 is an apocalyptic number.

It is an amenable number.

28181020281 is a deficient number, since it is larger than the sum of its proper divisors (9954490023).

28181020281 is a wasteful number, since it uses less digits than its factorization.

28181020281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 140204151.

The product of its (nonzero) digits is 4096, while the sum is 33.

The spelling of 28181020281 in words is "twenty-eight billion, one hundred eighty-one million, twenty thousand, two hundred eighty-one".