285372221 has 2 divisors, whose sum is σ = 285372222. Its totient is φ = 285372220.

The previous prime is 285372179. The next prime is 285372223. The reversal of 285372221 is 122273582.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 285136996 + 235225 = 16886^2 + 485^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-285372221 is a prime.

It is a super-3 number, since 3×285372221³ (a number of 26 digits) contains 333 as substring.

Together with 285372223, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (285372223) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 142686110 + 142686111.

It is an arithmetic number, because the mean of its divisors is an integer number (142686111).

Almost surely, 2^285372221 is an apocalyptic number.

It is an amenable number.

285372221 is a deficient number, since it is larger than the sum of its proper divisors (1).

285372221 is an equidigital number, since it uses as much as digits as its factorization.

285372221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 13440, while the sum is 32.

The square root of 285372221 is about 16892.9636535452. The cubic root of 285372221 is about 658.3708064482.

The spelling of 285372221 in words is "two hundred eighty-five million, three hundred seventy-two thousand, two hundred twenty-one".