630290981 has 2 divisors, whose sum is σ = 630290982. Its totient is φ = 630290980.

The previous prime is 630290957. The next prime is 630291001. The reversal of 630290981 is 189092036.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 470673025 + 159617956 = 21695^2 + 12634^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-630290981 is a prime.

It is a super-2 number, since 2×630290981² = 794533441459884722, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (630290951) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 315145490 + 315145491.

It is an arithmetic number, because the mean of its divisors is an integer number (315145491).

Almost surely, 2^630290981 is an apocalyptic number.

It is an amenable number.

630290981 is a deficient number, since it is larger than the sum of its proper divisors (1).

630290981 is an equidigital number, since it uses as much as digits as its factorization.

630290981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 23328, while the sum is 38.

The square root of 630290981 is about 25105.5966071312. The cubic root of 630290981 is about 857.3938504149.

The spelling of 630290981 in words is "six hundred thirty million, two hundred ninety thousand, nine hundred eighty-one".