28861721729321 has 8 divisors (see below), whose sum is σ = 32084494627584. Its totient is φ = 25782183182160.

The previous prime is 28861721729257. The next prime is 28861721729327. The reversal of 28861721729321 is 12392712716882.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 28861721729321 - 2⁶ = 28861721729257 is a prime.

It is a super-2 number, since 2×28861721729321² (a number of 28 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (28861721729327) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 35808587351 + ... + 35808588156.

It is an arithmetic number, because the mean of its divisors is an integer number (4010561828448).

Almost surely, 2^{28861721729321} is an apocalyptic number.

It is an amenable number.

28861721729321 is a deficient number, since it is larger than the sum of its proper divisors (3222772898263).

28861721729321 is a wasteful number, since it uses less digits than its factorization.

28861721729321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71617175551.

The product of its digits is 8128512, while the sum is 59.

The spelling of 28861721729321 in words is "twenty-eight trillion, eight hundred sixty-one billion, seven hundred twenty-one million, seven hundred twenty-nine thousand, three hundred twenty-one".