28724001538 has 8 divisors (see below), whose sum is σ = 43185509388. Its totient is φ = 14328831744.

The previous prime is 28724001517. The next prime is 28724001563. The reversal of 28724001538 is 83510042782.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 26340316209 + 2383685329 = 162297^2 + 48823^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a self number, because there is not a number n which added to its sum of digits gives 28724001538.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16583431 + ... + 16585162.

Almost surely, 2^28724001538 is an apocalyptic number.

28724001538 is a deficient number, since it is larger than the sum of its proper divisors (14461507850).

28724001538 is a wasteful number, since it uses less digits than its factorization.

28724001538 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33169028.

The product of its (nonzero) digits is 107520, while the sum is 40.

The spelling of 28724001538 in words is "twenty-eight billion, seven hundred twenty-four million, one thousand, five hundred thirty-eight".