28020821709468 has 48 divisors (see below), whose sum is σ = 78654938136320. Its totient is φ = 7584583319424.

The previous prime is 28020821709443. The next prime is 28020821709499. The reversal of 28020821709468 is 86490712802082.

It is a Harshad number since it is a multiple of its sum of digits (57).

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, 8778451321 + ... + 8778454512.

Almost surely, 2^{28020821709468} is an apocalyptic number.

28020821709468 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

28020821709468 is an abundant number, since it is smaller than the sum of its proper divisors (50634116426852).

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

28020821709468 is a wasteful number, since it uses less digits than its factorization.

28020821709468 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17556905866 (or 17556905864 counting only the distinct ones).

The product of its (nonzero) digits is 6193152, while the sum is 57.

The spelling of 28020821709468 in words is "twenty-eight trillion, twenty billion, eight hundred twenty-one million, seven hundred nine thousand, four hundred sixty-eight".