647737813221 has 8 divisors (see below), whose sum is σ = 863677817184. Its totient is φ = 431811509040.

The previous prime is 647737813201. The next prime is 647737813223. The reversal of 647737813221 is 122318737746.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 647737813221 - 2³⁰ = 646664071397 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (647737813223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3314110 + ... + 3504111.

It is an arithmetic number, because the mean of its divisors is an integer number (107959727148).

Almost surely, 2^647737813221 is an apocalyptic number.

It is an amenable number.

647737813221 is a deficient number, since it is larger than the sum of its proper divisors (215940003963).

647737813221 is a wasteful number, since it uses less digits than its factorization.

647737813221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6849891.

The product of its digits is 2370816, while the sum is 51.

The spelling of 647737813221 in words is "six hundred forty-seven billion, seven hundred thirty-seven million, eight hundred thirteen thousand, two hundred twenty-one".