28212557 has 2 divisors, whose sum is σ = 28212558. Its totient is φ = 28212556.

The previous prime is 28212523. The next prime is 28212617. The reversal of 28212557 is 75521282.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 22857961 + 5354596 = 4781^2 + 2314^2 .

It is a cyclic number.

It is not a de Polignac number, because 28212557 - 2¹⁴ = 28196173 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28212517) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14106278 + 14106279.

It is an arithmetic number, because the mean of its divisors is an integer number (14106279).

Almost surely, 2^28212557 is an apocalyptic number.

It is an amenable number.

28212557 is a deficient number, since it is larger than the sum of its proper divisors (1).

28212557 is an equidigital number, since it uses as much as digits as its factorization.

28212557 is an evil number, because the sum of its binary digits is even.

The product of its digits is 11200, while the sum is 32.

The square root of 28212557 is about 5311.5493973040. The cubic root of 28212557 is about 304.4253517438.

The spelling of 28212557 in words is "twenty-eight million, two hundred twelve thousand, five hundred fifty-seven".