647540651 has 4 divisors (see below), whose sum is σ = 647774472. Its totient is φ = 647306832.

The previous prime is 647540639. The next prime is 647540657. The reversal of 647540651 is 156045746.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-647540651 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (647540657) 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, 112706 + ... + 118311.

It is an arithmetic number, because the mean of its divisors is an integer number (161943618).

Almost surely, 2^647540651 is an apocalyptic number.

647540651 is a deficient number, since it is larger than the sum of its proper divisors (233821).

647540651 is a wasteful number, since it uses less digits than its factorization.

647540651 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 233820.

The product of its (nonzero) digits is 100800, while the sum is 38.

The square root of 647540651 is about 25446.8200567379. The cubic root of 647540651 is about 865.1452198076.

The spelling of 647540651 in words is "six hundred forty-seven million, five hundred forty thousand, six hundred fifty-one".