287047721 has 2 divisors, whose sum is σ = 287047722. Its totient is φ = 287047720.

The previous prime is 287047711. The next prime is 287047741. The reversal of 287047721 is 127740782.

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., 260370496 + 26677225 = 16136^2 + 5165^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-287047721 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (287047711) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 143523860 + 143523861.

It is an arithmetic number, because the mean of its divisors is an integer number (143523861).

Almost surely, 2^287047721 is an apocalyptic number.

It is an amenable number.

287047721 is a deficient number, since it is larger than the sum of its proper divisors (1).

287047721 is an equidigital number, since it uses as much as digits as its factorization.

287047721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 43904, while the sum is 38.

The square root of 287047721 is about 16942.4827283371. The cubic root of 287047721 is about 659.6567858926.

The spelling of 287047721 in words is "two hundred eighty-seven million, forty-seven thousand, seven hundred twenty-one".