630986921 has 4 divisors (see below), whose sum is σ = 631417344. Its totient is φ = 630556500.

The previous prime is 630986911. The next prime is 630986929. The reversal of 630986921 is 129689036.

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 not a de Polignac number, because 630986921 - 2¹⁸ = 630724777 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (630986929) 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, 213005 + ... + 215946.

It is an arithmetic number, because the mean of its divisors is an integer number (157854336).

Almost surely, 2^630986921 is an apocalyptic number.

It is an amenable number.

630986921 is a deficient number, since it is larger than the sum of its proper divisors (430423).

630986921 is a wasteful number, since it uses less digits than its factorization.

630986921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 430422.

The product of its (nonzero) digits is 139968, while the sum is 44.

The square root of 630986921 is about 25119.4530394274. The cubic root of 630986921 is about 857.7093000586.

The spelling of 630986921 in words is "six hundred thirty million, nine hundred eighty-six thousand, nine hundred twenty-one".