28402446221 has 4 divisors (see below), whose sum is σ = 28405053600. Its totient is φ = 28399838844.

The previous prime is 28402446211. The next prime is 28402446251. The reversal of 28402446221 is 12264420482.

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: 12264420482 = 2 ⋅6132210241.

It is a cyclic number.

It is not a de Polignac number, because 28402446221 - 2¹⁴ = 28402429837 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 (28402446211) 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, 1287281 + ... + 1309158.

It is an arithmetic number, because the mean of its divisors is an integer number (7101263400).

Almost surely, 2^28402446221 is an apocalyptic number.

It is an amenable number.

28402446221 is a deficient number, since it is larger than the sum of its proper divisors (2607379).

28402446221 is a wasteful number, since it uses less digits than its factorization.

28402446221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2607378.

The product of its (nonzero) digits is 49152, while the sum is 35.

The spelling of 28402446221 in words is "twenty-eight billion, four hundred two million, four hundred forty-six thousand, two hundred twenty-one".