28078081291 has 16 divisors (see below), whose sum is σ = 30993183648. Its totient is φ = 25271596800.

The previous prime is 28078081279. The next prime is 28078081309. The reversal of 28078081291 is 19218087082.

It is a cyclic number.

It is not a de Polignac number, because 28078081291 - 2¹⁹ = 28077557003 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28078081091) 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, 977760 + ... + 1006066.

It is an arithmetic number, because the mean of its divisors is an integer number (1937073978).

Almost surely, 2^28078081291 is an apocalyptic number.

28078081291 is a deficient number, since it is larger than the sum of its proper divisors (2915102357).

28078081291 is a wasteful number, since it uses less digits than its factorization.

28078081291 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30222.

The product of its (nonzero) digits is 129024, while the sum is 46.

The spelling of 28078081291 in words is "twenty-eight billion, seventy-eight million, eighty-one thousand, two hundred ninety-one".