1000630721 has 4 divisors (see below), whose sum is σ = 1001925972. Its totient is φ = 999335472.

The previous prime is 1000630717. The next prime is 1000630751. The reversal of 1000630721 is 1270360001.

It is a happy number.

1000630721 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1270360001 = 431 ⋅2947471.

It can be written as a sum of positive squares in 2 ways, for example, as 87684496 + 912946225 = 9364^2 + 30215^2 .

It is a cyclic number.

It is not a de Polignac number, because 1000630721 - 2² = 1000630717 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1000630693 and 1000630702.

It is not an unprimeable number, because it can be changed into a prime (1000630711) 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, 646466 + ... + 648011.

It is an arithmetic number, because the mean of its divisors is an integer number (250481493).

Almost surely, 2^1000630721 is an apocalyptic number.

It is an amenable number.

1000630721 is a deficient number, since it is larger than the sum of its proper divisors (1295251).

1000630721 is an equidigital number, since it uses as much as digits as its factorization.

1000630721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1295250.

The product of its (nonzero) digits is 252, while the sum is 20.

The square root of 1000630721 is about 31632.7476043419. The cubic root of 1000630721 is about 1000.2101961478.

Adding to 1000630721 its reverse (1270360001), we get a palindrome (2270990722).

The spelling of 1000630721 in words is "one billion, six hundred thirty thousand, seven hundred twenty-one".