647647355918 has 4 divisors (see below), whose sum is σ = 971471033880. Its totient is φ = 323823677958.

The previous prime is 647647355903. The next prime is 647647355933. The reversal of 647647355918 is 819553746746.

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

It is an interprime number because it is at equal distance from previous prime (647647355903) and next prime (647647355933).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 161911838978 + ... + 161911838981.

It is an arithmetic number, because the mean of its divisors is an integer number (242867758470).

Almost surely, 2^647647355918 is an apocalyptic number.

647647355918 is a deficient number, since it is larger than the sum of its proper divisors (323823677962).

647647355918 is a wasteful number, since it uses less digits than its factorization.

647647355918 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 323823677961.

The product of its digits is 152409600, while the sum is 65.

The spelling of 647647355918 in words is "six hundred forty-seven billion, six hundred forty-seven million, three hundred fifty-five thousand, nine hundred eighteen".