647404129 has 2 divisors, whose sum is σ = 647404130. Its totient is φ = 647404128.

The previous prime is 647404099. The next prime is 647404139. The reversal of 647404129 is 921404746.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 382593600 + 264810529 = 19560^2 + 16273^2 .

It is a cyclic number.

It is not a de Polignac number, because 647404129 - 2²⁵ = 613849697 is a prime.

It is not a weakly prime, because it can be changed into another prime (647404139) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323702064 + 323702065.

It is an arithmetic number, because the mean of its divisors is an integer number (323702065).

Almost surely, 2^647404129 is an apocalyptic number.

It is an amenable number.

647404129 is a deficient number, since it is larger than the sum of its proper divisors (1).

647404129 is an equidigital number, since it uses as much as digits as its factorization.

647404129 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 48384, while the sum is 37.

The square root of 647404129 is about 25444.1374190598. The cubic root of 647404129 is about 865.0844155646.

The spelling of 647404129 in words is "six hundred forty-seven million, four hundred four thousand, one hundred twenty-nine".