28922021 has 2 divisors, whose sum is σ = 28922022. Its totient is φ = 28922020.

The previous prime is 28921999. The next prime is 28922029. The reversal of 28922021 is 12022982.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 24453025 + 4468996 = 4945^2 + 2114^2 .

It is a cyclic number.

It is not a de Polignac number, because 28922021 - 2¹⁴ = 28905637 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28922029) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14461010 + 14461011.

It is an arithmetic number, because the mean of its divisors is an integer number (14461011).

Almost surely, 2^28922021 is an apocalyptic number.

It is an amenable number.

28922021 is a deficient number, since it is larger than the sum of its proper divisors (1).

28922021 is an equidigital number, since it uses as much as digits as its factorization.

28922021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1152, while the sum is 26.

The square root of 28922021 is about 5377.9197651136. The cubic root of 28922021 is about 306.9560604425.

It can be divided in two parts, 2892 and 2021, that added together give a cube (4913 = 17³).

The spelling of 28922021 in words is "twenty-eight million, nine hundred twenty-two thousand, twenty-one".