28391913155 has 4 divisors (see below), whose sum is σ = 34070295792. Its totient is φ = 22713530520.

The previous prime is 28391913133. The next prime is 28391913157. The reversal of 28391913155 is 55131919382.

It is a happy number.

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

It is not a de Polignac number, because 28391913155 - 2¹⁶ = 28391847619 is a prime.

It is a super-2 number, since 2×28391913155² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28391913157) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2839191311 + ... + 2839191320.

It is an arithmetic number, because the mean of its divisors is an integer number (8517573948).

Almost surely, 2^28391913155 is an apocalyptic number.

28391913155 is a deficient number, since it is larger than the sum of its proper divisors (5678382637).

28391913155 is an equidigital number, since it uses as much as digits as its factorization.

28391913155 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5678382636.

The product of its digits is 291600, while the sum is 47.

The spelling of 28391913155 in words is "twenty-eight billion, three hundred ninety-one million, nine hundred thirteen thousand, one hundred fifty-five".