28213261 has 2 divisors, whose sum is σ = 28213262. Its totient is φ = 28213260.

The previous prime is 28213253. The next prime is 28213279. The reversal of 28213261 is 16231282.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 28196100 + 17161 = 5310^2 + 131^2 .

It is a cyclic number.

It is not a de Polignac number, because 28213261 - 2³ = 28213253 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28213561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14106630 + 14106631.

It is an arithmetic number, because the mean of its divisors is an integer number (14106631).

Almost surely, 2^28213261 is an apocalyptic number.

It is an amenable number.

28213261 is a deficient number, since it is larger than the sum of its proper divisors (1).

28213261 is an equidigital number, since it uses as much as digits as its factorization.

28213261 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1152, while the sum is 25.

The square root of 28213261 is about 5311.6156675723. The cubic root of 28213261 is about 304.4278838747.

The spelling of 28213261 in words is "twenty-eight million, two hundred thirteen thousand, two hundred sixty-one".