647881511 has 4 divisors (see below), whose sum is σ = 661666272. Its totient is φ = 634096752.

The previous prime is 647881501. The next prime is 647881529. The reversal of 647881511 is 115188746.

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 647881511 - 2¹⁸ = 647619367 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (647881501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6892310 + ... + 6892403.

It is an arithmetic number, because the mean of its divisors is an integer number (165416568).

Almost surely, 2^647881511 is an apocalyptic number.

647881511 is a deficient number, since it is larger than the sum of its proper divisors (13784761).

647881511 is a wasteful number, since it uses less digits than its factorization.

647881511 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13784760.

The product of its digits is 53760, while the sum is 41.

The square root of 647881511 is about 25453.5166725543. The cubic root of 647881511 is about 865.2969949232.

The spelling of 647881511 in words is "six hundred forty-seven million, eight hundred eighty-one thousand, five hundred eleven".