28867812781 has 8 divisors (see below), whose sum is σ = 29170691264. Its totient is φ = 28565369280.

The previous prime is 28867812767. The next prime is 28867812793. The reversal of 28867812781 is 18721876882.

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

It is a cyclic number.

It is not a de Polignac number, because 28867812781 - 2⁹ = 28867812269 is a prime.

It is a super-2 number, since 2×28867812781² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28867812881) 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, 25546 + ... + 241636.

It is an arithmetic number, because the mean of its divisors is an integer number (3646336408).

Almost surely, 2^28867812781 is an apocalyptic number.

It is an amenable number.

28867812781 is a deficient number, since it is larger than the sum of its proper divisors (302878483).

28867812781 is a wasteful number, since it uses less digits than its factorization.

28867812781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 217491.

The product of its digits is 4816896, while the sum is 58.

The spelling of 28867812781 in words is "twenty-eight billion, eight hundred sixty-seven million, eight hundred twelve thousand, seven hundred eighty-one".