28251991992 has 64 divisors (see below), whose sum is σ = 80732517120. Its totient is φ = 8070743808.

The previous prime is 28251991973. The next prime is 28251992059. The reversal of 28251991992 is 29919915282.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1924183 + ... + 1938809.

It is an arithmetic number, because the mean of its divisors is an integer number (1261445580).

Almost surely, 2^28251991992 is an apocalyptic number.

It is an amenable number.

28251991992 is an abundant number, since it is smaller than the sum of its proper divisors (52480525128).

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

28251991992 is a wasteful number, since it uses less digits than its factorization.

28251991992 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26140 (or 26136 counting only the distinct ones).

The product of its digits is 2099520, while the sum is 57.

The spelling of 28251991992 in words is "twenty-eight billion, two hundred fifty-one million, nine hundred ninety-one thousand, nine hundred ninety-two".