28931511361 has 4 divisors (see below), whose sum is σ = 29104754112. Its totient is φ = 28758268612.

The previous prime is 28931511317. The next prime is 28931511373. The reversal of 28931511361 is 16311513982.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 28931511361 - 2⁹ = 28931510849 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28931514361) 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, 86621125 + ... + 86621458.

It is an arithmetic number, because the mean of its divisors is an integer number (7276188528).

Almost surely, 2^28931511361 is an apocalyptic number.

It is an amenable number.

28931511361 is a deficient number, since it is larger than the sum of its proper divisors (173242751).

28931511361 is a wasteful number, since it uses less digits than its factorization.

28931511361 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 173242750.

The product of its digits is 38880, while the sum is 40.

The spelling of 28931511361 in words is "twenty-eight billion, nine hundred thirty-one million, five hundred eleven thousand, three hundred sixty-one".