28421720613 has 96 divisors (see below), whose sum is σ = 50363376000. Its totient is φ = 15734062080.

The previous prime is 28421720611. The next prime is 28421720617. The reversal of 28421720613 is 31602712482.

It is a happy number.

28421720613 is a `hidden beast` number, since 2 + 8 + 4 + 2 + 17 + 20 + 613 = 666.

It is not a de Polignac number, because 28421720613 - 2¹ = 28421720611 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28421720611) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 4116238 + ... + 4123136.

It is an arithmetic number, because the mean of its divisors is an integer number (524618500).

Almost surely, 2^28421720613 is an apocalyptic number.

It is an amenable number.

28421720613 is a deficient number, since it is larger than the sum of its proper divisors (21941655387).

28421720613 is a wasteful number, since it uses less digits than its factorization.

28421720613 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7040 (or 7023 counting only the distinct ones).

The product of its (nonzero) digits is 32256, while the sum is 36.

The spelling of 28421720613 in words is "twenty-eight billion, four hundred twenty-one million, seven hundred twenty thousand, six hundred thirteen".