28357016721 has 16 divisors (see below), whose sum is σ = 41253382848. Its totient is φ = 17183232000.

The previous prime is 28357016717. The next prime is 28357016731. The reversal of 28357016721 is 12761075382.

It is not a de Polignac number, because 28357016721 - 2² = 28357016717 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28357016731) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 141321 + ... + 276921.

It is an arithmetic number, because the mean of its divisors is an integer number (2578336428).

Almost surely, 2^28357016721 is an apocalyptic number.

It is an amenable number.

28357016721 is a deficient number, since it is larger than the sum of its proper divisors (12896366127).

28357016721 is a wasteful number, since it uses less digits than its factorization.

28357016721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 141952.

The product of its (nonzero) digits is 141120, while the sum is 42.

The spelling of 28357016721 in words is "twenty-eight billion, three hundred fifty-seven million, sixteen thousand, seven hundred twenty-one".