247388221 has 2 divisors, whose sum is σ = 247388222. Its totient is φ = 247388220.

The previous prime is 247388201. The next prime is 247388231. The reversal of 247388221 is 122883742.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 195692121 + 51696100 = 13989^2 + 7190^2 .

It is a cyclic number.

It is not a de Polignac number, because 247388221 - 2⁷ = 247388093 is a prime.

It is a super-2 number, since 2×247388221² = 122401863779089682, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (247388201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 123694110 + 123694111.

It is an arithmetic number, because the mean of its divisors is an integer number (123694111).

Almost surely, 2^247388221 is an apocalyptic number.

It is an amenable number.

247388221 is a deficient number, since it is larger than the sum of its proper divisors (1).

247388221 is an equidigital number, since it uses as much as digits as its factorization.

247388221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 43008, while the sum is 37.

The square root of 247388221 is about 15728.5797515224. The cubic root of 247388221 is about 627.7590839263.

The spelling of 247388221 in words is "two hundred forty-seven million, three hundred eighty-eight thousand, two hundred twenty-one".