728788139 has 4 divisors (see below), whose sum is σ = 735863856. Its totient is φ = 721712424.

The previous prime is 728788117. The next prime is 728788141. The reversal of 728788139 is 931887827.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-728788139 is a prime.

It is a super-2 number, since 2×728788139² = 1062264303094166642, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (728788169) 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, 3537704 + ... + 3537909.

It is an arithmetic number, because the mean of its divisors is an integer number (183965964).

Almost surely, 2^728788139 is an apocalyptic number.

728788139 is a deficient number, since it is larger than the sum of its proper divisors (7075717).

728788139 is a wasteful number, since it uses less digits than its factorization.

728788139 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7075716.

The product of its digits is 1354752, while the sum is 53.

The square root of 728788139 is about 26996.0763630569. The cubic root of 728788139 is about 899.9128059560.

The spelling of 728788139 in words is "seven hundred twenty-eight million, seven hundred eighty-eight thousand, one hundred thirty-nine".