247941721 has 2 divisors, whose sum is σ = 247941722. Its totient is φ = 247941720.

The previous prime is 247941691. The next prime is 247941731. The reversal of 247941721 is 127149742.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 221563225 + 26378496 = 14885^2 + 5136^2 .

It is a cyclic number.

It is not a de Polignac number, because 247941721 - 2¹³ = 247933529 is a prime.

It is a super-2 number, since 2×247941721² = 122950194024883682, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (247941731) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 123970860 + 123970861.

It is an arithmetic number, because the mean of its divisors is an integer number (123970861).

Almost surely, 2^247941721 is an apocalyptic number.

It is an amenable number.

247941721 is a deficient number, since it is larger than the sum of its proper divisors (1).

247941721 is an equidigital number, since it uses as much as digits as its factorization.

247941721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 28224, while the sum is 37.

The square root of 247941721 is about 15746.1652792037. The cubic root of 247941721 is about 628.2269125036.

The spelling of 247941721 in words is "two hundred forty-seven million, nine hundred forty-one thousand, seven hundred twenty-one".