28989421785 has 48 divisors (see below), whose sum is σ = 53231952384. Its totient is φ = 14543940096.

The previous prime is 28989421781. The next prime is 28989421807. The reversal of 28989421785 is 58712498982.

It is not a de Polignac number, because 28989421785 - 2² = 28989421781 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28989421781) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1630554 + ... + 1648236.

It is an arithmetic number, because the mean of its divisors is an integer number (1108999008).

Almost surely, 2^28989421785 is an apocalyptic number.

It is an amenable number.

28989421785 is a deficient number, since it is larger than the sum of its proper divisors (24242530599).

28989421785 is a wasteful number, since it uses less digits than its factorization.

28989421785 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19854 (or 19851 counting only the distinct ones).

The product of its digits is 23224320, while the sum is 63.

The spelling of 28989421785 in words is "twenty-eight billion, nine hundred eighty-nine million, four hundred twenty-one thousand, seven hundred eighty-five".