647238407 has 2 divisors, whose sum is σ = 647238408. Its totient is φ = 647238406.

The previous prime is 647238379. The next prime is 647238409. The reversal of 647238407 is 704832746.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 647238407 - 2¹² = 647234311 is a prime.

Together with 647238409, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (647238409) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323619203 + 323619204.

It is an arithmetic number, because the mean of its divisors is an integer number (323619204).

Almost surely, 2^647238407 is an apocalyptic number.

647238407 is a deficient number, since it is larger than the sum of its proper divisors (1).

647238407 is an equidigital number, since it uses as much as digits as its factorization.

647238407 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 225792, while the sum is 41.

The square root of 647238407 is about 25440.8806254815. The cubic root of 647238407 is about 865.0105947225.

The spelling of 647238407 in words is "six hundred forty-seven million, two hundred thirty-eight thousand, four hundred seven".