728122091987 has 16 divisors (see below), whose sum is σ = 746091702432. Its totient is φ = 710319267840.

The previous prime is 728122091971. The next prime is 728122092023. The reversal of 728122091987 is 789190221827.

It is a cyclic number.

It is not a de Polignac number, because 728122091987 - 2⁴ = 728122091971 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (728122091287) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7538912 + ... + 7634882.

It is an arithmetic number, because the mean of its divisors is an integer number (46630731402).

Almost surely, 2^728122091987 is an apocalyptic number.

728122091987 is a deficient number, since it is larger than the sum of its proper divisors (17969610445).

728122091987 is a wasteful number, since it uses less digits than its factorization.

728122091987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 96838.

The product of its (nonzero) digits is 2032128, while the sum is 56.

The spelling of 728122091987 in words is "seven hundred twenty-eight billion, one hundred twenty-two million, ninety-one thousand, nine hundred eighty-seven".