247649 has 2 divisors, whose sum is σ = 247650. Its totient is φ = 247648.

The previous prime is 247633. The next prime is 247651. The reversal of 247649 is 946742.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 135424 + 112225 = 368^2 + 335^2 .

It is a cyclic number.

It is not a de Polignac number, because 247649 - 2⁴ = 247633 is a prime.

It is a super-2 number, since 2×247649² = 122660054402, which contains 22 as substring.

Together with 247651, it forms a pair of twin primes.

It is a Chen prime.

It is an Ulam number.

It is not a weakly prime, because it can be changed into another prime (247609) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 123824 + 123825.

It is an arithmetic number, because the mean of its divisors is an integer number (123825).

2²⁴⁷⁶⁴⁹ is an apocalyptic number.

It is an amenable number.

247649 is a deficient number, since it is larger than the sum of its proper divisors (1).

247649 is an equidigital number, since it uses as much as digits as its factorization.

247649 is an evil number, because the sum of its binary digits is even.

The product of its digits is 12096, while the sum is 32.

The square root of 247649 is about 497.6434466563. The cubic root of 247649 is about 62.7979586067.

The spelling of 247649 in words is "two hundred forty-seven thousand, six hundred forty-nine".