647434561 has 2 divisors, whose sum is σ = 647434562. Its totient is φ = 647434560.

The previous prime is 647434549. The next prime is 647434573. The reversal of 647434561 is 165434746.

It is a balanced prime because it is at equal distance from previous prime (647434549) and next prime (647434573).

It can be written as a sum of positive squares in only one way, i.e., 469372225 + 178062336 = 21665^2 + 13344^2 .

It is a cyclic number.

It is not a de Polignac number, because 647434561 - 2⁷ = 647434433 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (647432561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323717280 + 323717281.

It is an arithmetic number, because the mean of its divisors is an integer number (323717281).

Almost surely, 2^647434561 is an apocalyptic number.

It is an amenable number.

647434561 is a deficient number, since it is larger than the sum of its proper divisors (1).

647434561 is an equidigital number, since it uses as much as digits as its factorization.

647434561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 241920, while the sum is 40.

The square root of 647434561 is about 25444.7354279820. The cubic root of 647434561 is about 865.0979701257.

The spelling of 647434561 in words is "six hundred forty-seven million, four hundred thirty-four thousand, five hundred sixty-one".