28328632639 has 4 divisors (see below), whose sum is σ = 28343710960. Its totient is φ = 28313554320.

The previous prime is 28328632637. The next prime is 28328632643. The reversal of 28328632639 is 93623682382.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 28328632639 - 2¹ = 28328632637 is a prime.

It is a super-2 number, since 2×28328632639² (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 (28328632637) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7536342 + ... + 7540099.

It is an arithmetic number, because the mean of its divisors is an integer number (7085927740).

Almost surely, 2^28328632639 is an apocalyptic number.

28328632639 is a deficient number, since it is larger than the sum of its proper divisors (15078321).

28328632639 is a wasteful number, since it uses less digits than its factorization.

28328632639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15078320.

The product of its digits is 4478976, while the sum is 52.

The spelling of 28328632639 in words is "twenty-eight billion, three hundred twenty-eight million, six hundred thirty-two thousand, six hundred thirty-nine".