28661199389 has 12 divisors (see below), whose sum is σ = 29627906652. Its totient is φ = 27725100480.

The previous prime is 28661199373. The next prime is 28661199433. The reversal of 28661199389 is 98399116682.

It can be written as a sum of positive squares in 2 ways, for example, as 14096812900 + 14564386489 = 118730^2 + 120683^2 .

It is not a de Polignac number, because 28661199389 - 2⁴ = 28661199373 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28661199319) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3125399 + ... + 3134555.

It is an arithmetic number, because the mean of its divisors is an integer number (2468992221).

Almost surely, 2^28661199389 is an apocalyptic number.

It is an amenable number.

28661199389 is a deficient number, since it is larger than the sum of its proper divisors (966707263).

28661199389 is an equidigital number, since it uses as much as digits as its factorization.

28661199389 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12476 (or 12445 counting only the distinct ones).

The product of its digits is 10077696, while the sum is 62.

The spelling of 28661199389 in words is "twenty-eight billion, six hundred sixty-one million, one hundred ninety-nine thousand, three hundred eighty-nine".