287172521 has 2 divisors, whose sum is σ = 287172522. Its totient is φ = 287172520.

The previous prime is 287172481. The next prime is 287172539. The reversal of 287172521 is 125271782.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 244453225 + 42719296 = 15635^2 + 6536^2 .

It is a cyclic number.

It is not a de Polignac number, because 287172521 - 2²² = 282978217 is a prime.

It is not a weakly prime, because it can be changed into another prime (287172421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 143586260 + 143586261.

It is an arithmetic number, because the mean of its divisors is an integer number (143586261).

Almost surely, 2^287172521 is an apocalyptic number.

It is an amenable number.

287172521 is a deficient number, since it is larger than the sum of its proper divisors (1).

287172521 is an equidigital number, since it uses as much as digits as its factorization.

287172521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 15680, while the sum is 35.

The square root of 287172521 is about 16946.1653774534. The cubic root of 287172521 is about 659.7523719025.

The spelling of 287172521 in words is "two hundred eighty-seven million, one hundred seventy-two thousand, five hundred twenty-one".