28287178361 has 4 divisors (see below), whose sum is σ = 30463115172. Its totient is φ = 26111241552.

The previous prime is 28287178349. The next prime is 28287178411. The reversal of 28287178361 is 16387178282.

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

It can be written as a sum of positive squares in 2 ways, for example, as 10047055225 + 18240123136 = 100235^2 + 135056^2 .

It is a cyclic number.

It is not a de Polignac number, because 28287178361 - 2¹⁰ = 28287177337 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28287178331) 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, 1087968386 + ... + 1087968411.

It is an arithmetic number, because the mean of its divisors is an integer number (7615778793).

Almost surely, 2^28287178361 is an apocalyptic number.

It is an amenable number.

28287178361 is a deficient number, since it is larger than the sum of its proper divisors (2175936811).

28287178361 is a wasteful number, since it uses less digits than its factorization.

28287178361 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2175936810.

The product of its digits is 1806336, while the sum is 53.

The spelling of 28287178361 in words is "twenty-eight billion, two hundred eighty-seven million, one hundred seventy-eight thousand, three hundred sixty-one".