28196056621 has 4 divisors (see below), whose sum is σ = 28851778912. Its totient is φ = 27540334332.

The previous prime is 28196056619. The next prime is 28196056631. The reversal of 28196056621 is 12665069182.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 12665069182 = 2 ⋅6332534591.

It is a cyclic number.

It is not a de Polignac number, because 28196056621 - 2¹ = 28196056619 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28196056631) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 327861081 + ... + 327861166.

It is an arithmetic number, because the mean of its divisors is an integer number (7212944728).

Almost surely, 2^28196056621 is an apocalyptic number.

It is an amenable number.

28196056621 is a deficient number, since it is larger than the sum of its proper divisors (655722291).

28196056621 is an equidigital number, since it uses as much as digits as its factorization.

28196056621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 655722290.

The product of its (nonzero) digits is 311040, while the sum is 46.

The spelling of 28196056621 in words is "twenty-eight billion, one hundred ninety-six million, fifty-six thousand, six hundred twenty-one".