647381647 has 4 divisors (see below), whose sum is σ = 706234536. Its totient is φ = 588528760.

The previous prime is 647381617. The next prime is 647381653. The reversal of 647381647 is 746183746.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 647381647 - 2²⁷ = 513163919 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 647381597 and 647381606.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (647381617) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 29426428 + ... + 29426449.

It is an arithmetic number, because the mean of its divisors is an integer number (176558634).

Almost surely, 2^647381647 is an apocalyptic number.

647381647 is a deficient number, since it is larger than the sum of its proper divisors (58852889).

647381647 is a wasteful number, since it uses less digits than its factorization.

647381647 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 58852888.

The product of its digits is 677376, while the sum is 46.

The square root of 647381647 is about 25443.6956238672. The cubic root of 647381647 is about 865.0744016994.

The spelling of 647381647 in words is "six hundred forty-seven million, three hundred eighty-one thousand, six hundred forty-seven".