21729303240828 has 48 divisors (see below), whose sum is σ = 53684737747200. Its totient is φ = 6816963066624.

The previous prime is 21729303240751. The next prime is 21729303240847. The reversal of 21729303240828 is 82804230392712.

It is a super-3 number, since 3×21729303240828³ (a number of 41 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a hoax number, since the sum of its digits (51) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (51).

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, 20327475 + ... + 21369717.

It is an arithmetic number, because the mean of its divisors is an integer number (1118432036400).

Almost surely, 2^{21729303240828} is an apocalyptic number.

It is an amenable number.

21729303240828 is an abundant number, since it is smaller than the sum of its proper divisors (31955434506372).

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

21729303240828 is a wasteful number, since it uses less digits than its factorization.

21729303240828 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1144466 (or 1144464 counting only the distinct ones).

The product of its (nonzero) digits is 2322432, while the sum is 51.

The spelling of 21729303240828 in words is "twenty-one trillion, seven hundred twenty-nine billion, three hundred three million, two hundred forty thousand, eight hundred twenty-eight".