28621654189 has 4 divisors (see below), whose sum is σ = 30305280924. Its totient is φ = 26938027456.

The previous prime is 28621654157. The next prime is 28621654199. The reversal of 28621654189 is 98145612682.

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 21776904900 + 6844749289 = 147570^2 + 82733^2 .

It is a cyclic number.

It is not a de Polignac number, because 28621654189 - 2⁵ = 28621654157 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 (28621654199) 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, 841813342 + ... + 841813375.

It is an arithmetic number, because the mean of its divisors is an integer number (7576320231).

Almost surely, 2^28621654189 is an apocalyptic number.

It is an amenable number.

28621654189 is a deficient number, since it is larger than the sum of its proper divisors (1683626735).

28621654189 is a wasteful number, since it uses less digits than its factorization.

28621654189 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1683626734.

The product of its digits is 1658880, while the sum is 52.

The spelling of 28621654189 in words is "twenty-eight billion, six hundred twenty-one million, six hundred fifty-four thousand, one hundred eighty-nine".