247561609 has 2 divisors, whose sum is σ = 247561610. Its totient is φ = 247561608.

The previous prime is 247561591. The next prime is 247561619. The reversal of 247561609 is 906165742.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 244766025 + 2795584 = 15645^2 + 1672^2 .

It is a cyclic number.

It is not a de Polignac number, because 247561609 - 2¹⁷ = 247430537 is a prime.

It is a super-2 number, since 2×247561609² = 122573500501337762, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (247561619) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 123780804 + 123780805.

It is an arithmetic number, because the mean of its divisors is an integer number (123780805).

Almost surely, 2^247561609 is an apocalyptic number.

It is an amenable number.

247561609 is a deficient number, since it is larger than the sum of its proper divisors (1).

247561609 is an equidigital number, since it uses as much as digits as its factorization.

247561609 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 90720, while the sum is 40.

The square root of 247561609 is about 15734.0906632700. The cubic root of 247561609 is about 627.9057097066.

The spelling of 247561609 in words is "two hundred forty-seven million, five hundred sixty-one thousand, six hundred nine".