28620217 has 2 divisors, whose sum is σ = 28620218. Its totient is φ = 28620216.

The previous prime is 28620209. The next prime is 28620247. The reversal of 28620217 is 71202682.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15832441 + 12787776 = 3979^2 + 3576^2 .

It is a cyclic number.

It is not a de Polignac number, because 28620217 - 2³ = 28620209 is a prime.

It is a super-2 number, since 2×28620217² = 1638233642254178, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (28620247) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14310108 + 14310109.

It is an arithmetic number, because the mean of its divisors is an integer number (14310109).

Almost surely, 2^28620217 is an apocalyptic number.

It is an amenable number.

28620217 is a deficient number, since it is larger than the sum of its proper divisors (1).

28620217 is an equidigital number, since it uses as much as digits as its factorization.

28620217 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2688, while the sum is 28.

The square root of 28620217 is about 5349.7866312592. The cubic root of 28620217 is about 305.8846198064.

Adding to 28620217 its reverse (71202682), we get a palindrome (99822899).

It can be divided in two parts, 2862021 and 7, that added together give a triangular number (2862028 = T₂₃₉₂).

The spelling of 28620217 in words is "twenty-eight million, six hundred twenty thousand, two hundred seventeen".