28387935781 has 8 divisors (see below), whose sum is σ = 28677182144. Its totient is φ = 28098951840.

The previous prime is 28387935767. The next prime is 28387935799. The reversal of 28387935781 is 18753978382.

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 28387935781 - 2⁹ = 28387935269 is a prime.

It is a super-2 number, since 2×28387935781² (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 (28387935181) 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, 155626 + ... + 284596.

It is an arithmetic number, because the mean of its divisors is an integer number (3584647768).

Almost surely, 2^28387935781 is an apocalyptic number.

It is an amenable number.

28387935781 is a deficient number, since it is larger than the sum of its proper divisors (289246363).

28387935781 is a wasteful number, since it uses less digits than its factorization.

28387935781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 131211.

The product of its digits is 20321280, while the sum is 61.

The spelling of 28387935781 in words is "twenty-eight billion, three hundred eighty-seven million, nine hundred thirty-five thousand, seven hundred eighty-one".