647653729 has 2 divisors, whose sum is σ = 647653730. Its totient is φ = 647653728.

The previous prime is 647653697. The next prime is 647653733. The reversal of 647653729 is 927356746.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 643129600 + 4524129 = 25360^2 + 2127^2 .

It is a cyclic number.

It is not a de Polignac number, because 647653729 - 2⁵ = 647653697 is a prime.

It is not a weakly prime, because it can be changed into another prime (647653129) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323826864 + 323826865.

It is an arithmetic number, because the mean of its divisors is an integer number (323826865).

Almost surely, 2^647653729 is an apocalyptic number.

It is an amenable number.

647653729 is a deficient number, since it is larger than the sum of its proper divisors (1).

647653729 is an equidigital number, since it uses as much as digits as its factorization.

647653729 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1905120, while the sum is 49.

The square root of 647653729 is about 25449.0418090741. The cubic root of 647653729 is about 865.1955760784.

The spelling of 647653729 in words is "six hundred forty-seven million, six hundred fifty-three thousand, seven hundred twenty-nine".