630766721 has 4 divisors (see below), whose sum is σ = 679287252. Its totient is φ = 582246192.

The previous prime is 630766687. The next prime is 630766729. The reversal of 630766721 is 127667036.

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

It can be written as a sum of positive squares in 2 ways, for example, as 126315121 + 504451600 = 11239^2 + 22460^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-630766721 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (630766729) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 24260246 + ... + 24260271.

It is an arithmetic number, because the mean of its divisors is an integer number (169821813).

Almost surely, 2^630766721 is an apocalyptic number.

It is an amenable number.

630766721 is a deficient number, since it is larger than the sum of its proper divisors (48520531).

630766721 is a wasteful number, since it uses less digits than its factorization.

630766721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48520530.

The product of its (nonzero) digits is 63504, while the sum is 38.

The square root of 630766721 is about 25115.0695997443. The cubic root of 630766721 is about 857.6095148089.

The spelling of 630766721 in words is "six hundred thirty million, seven hundred sixty-six thousand, seven hundred twenty-one".