28920633409 has 4 divisors (see below), whose sum is σ = 29917896660. Its totient is φ = 27923370160.

The previous prime is 28920633383. The next prime is 28920633431. The reversal of 28920633409 is 90433602982.

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 7118634384 + 21801999025 = 84372^2 + 147655^2 .

It is a cyclic number.

It is not a de Polignac number, because 28920633409 - 2²⁹ = 28383762497 is a prime.

It is a super-2 number, since 2×28920633409² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28920633449) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 498631582 + ... + 498631639.

It is an arithmetic number, because the mean of its divisors is an integer number (7479474165).

Almost surely, 2^28920633409 is an apocalyptic number.

28920633409 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

It is an amenable number.

28920633409 is a deficient number, since it is larger than the sum of its proper divisors (997263251).

28920633409 is an equidigital number, since it uses as much as digits as its factorization.

28920633409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 997263250.

The product of its (nonzero) digits is 559872, while the sum is 46.

The spelling of 28920633409 in words is "twenty-eight billion, nine hundred twenty million, six hundred thirty-three thousand, four hundred nine".