28329221391 has 8 divisors (see below), whose sum is σ = 37774835760. Its totient is φ = 18884877312.

The previous prime is 28329221359. The next prime is 28329221399. The reversal of 28329221391 is 19312292382.

It is a happy number.

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

It is not a de Polignac number, because 28329221391 - 2⁵ = 28329221359 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28329221399) 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, 264256 + ... + 355653.

It is an arithmetic number, because the mean of its divisors is an integer number (4721854470).

Almost surely, 2^28329221391 is an apocalyptic number.

28329221391 is a deficient number, since it is larger than the sum of its proper divisors (9445614369).

28329221391 is a wasteful number, since it uses less digits than its factorization.

28329221391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 635145.

The product of its digits is 93312, while the sum is 42.

The spelling of 28329221391 in words is "twenty-eight billion, three hundred twenty-nine million, two hundred twenty-one thousand, three hundred ninety-one".