647549801 has 2 divisors, whose sum is σ = 647549802. Its totient is φ = 647549800.

The previous prime is 647549767. The next prime is 647549803. The reversal of 647549801 is 108945746.

647549801 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 571162201 + 76387600 = 23899^2 + 8740^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-647549801 is a prime.

Together with 647549803, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (647549803) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323774900 + 323774901.

It is an arithmetic number, because the mean of its divisors is an integer number (323774901).

Almost surely, 2^647549801 is an apocalyptic number.

It is an amenable number.

647549801 is a deficient number, since it is larger than the sum of its proper divisors (1).

647549801 is an equidigital number, since it uses as much as digits as its factorization.

647549801 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 241920, while the sum is 44.

The square root of 647549801 is about 25446.9998428105. Note that the first 3 decimals coincide. The cubic root of 647549801 is about 865.1492947340.

The spelling of 647549801 in words is "six hundred forty-seven million, five hundred forty-nine thousand, eight hundred one".