28891661200 has 30 divisors (see below), whose sum is σ = 69412216994. Its totient is φ = 11556664320.

The previous prime is 28891661167. The next prime is 28891661203. The reversal of 28891661200 is 216619882.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 2382611344 + 26509049856 = 48812^2 + 162816^2 .

It is not an unprimeable number, because it can be changed into a prime (28891661203) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 36114177 + ... + 36114976.

Almost surely, 2^28891661200 is an apocalyptic number.

28891661200 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28891661200 is an abundant number, since it is smaller than the sum of its proper divisors (40520555794).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

28891661200 is a wasteful number, since it uses less digits than its factorization.

28891661200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72229171 (or 72229160 counting only the distinct ones).

The product of its (nonzero) digits is 82944, while the sum is 43.

The spelling of 28891661200 in words is "twenty-eight billion, eight hundred ninety-one million, six hundred sixty-one thousand, two hundred".