631228901 has 2 divisors, whose sum is σ = 631228902. Its totient is φ = 631228900.

The previous prime is 631228841. The next prime is 631228903. The reversal of 631228901 is 109822136.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 375196900 + 256032001 = 19370^2 + 16001^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-631228901 is a prime.

It is a Sophie Germain prime.

Together with 631228903, it forms a pair of twin primes.

It is a Chen 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 (631228903) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 315614450 + 315614451.

It is an arithmetic number, because the mean of its divisors is an integer number (315614451).

Almost surely, 2^631228901 is an apocalyptic number.

It is an amenable number.

631228901 is a deficient number, since it is larger than the sum of its proper divisors (1).

631228901 is an equidigital number, since it uses as much as digits as its factorization.

631228901 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5184, while the sum is 32.

The square root of 631228901 is about 25124.2691635001. The cubic root of 631228901 is about 857.8189283060.

The spelling of 631228901 in words is "six hundred thirty-one million, two hundred twenty-eight thousand, nine hundred one".