630665640521 has 4 divisors (see below), whose sum is σ = 720760732032. Its totient is φ = 540570549012.

The previous prime is 630665640503. The next prime is 630665640541. The reversal of 630665640521 is 125046566036.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-630665640521 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (630665640541) 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, 45047545745 + ... + 45047545758.

It is an arithmetic number, because the mean of its divisors is an integer number (180190183008).

Almost surely, 2^630665640521 is an apocalyptic number.

It is an amenable number.

630665640521 is a deficient number, since it is larger than the sum of its proper divisors (90095091511).

630665640521 is an equidigital number, since it uses as much as digits as its factorization.

630665640521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 90095091510.

The product of its (nonzero) digits is 777600, while the sum is 44.

The spelling of 630665640521 in words is "six hundred thirty billion, six hundred sixty-five million, six hundred forty thousand, five hundred twenty-one".