631806421 has 2 divisors, whose sum is σ = 631806422. Its totient is φ = 631806420.

The previous prime is 631806403. The next prime is 631806437. The reversal of 631806421 is 124608136.

It is a happy number.

631806421 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 496665796 + 135140625 = 22286^2 + 11625^2 .

It is a cyclic number.

It is not a de Polignac number, because 631806421 - 2¹¹ = 631804373 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (631806451) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 315903210 + 315903211.

It is an arithmetic number, because the mean of its divisors is an integer number (315903211).

Almost surely, 2^631806421 is an apocalyptic number.

It is an amenable number.

631806421 is a deficient number, since it is larger than the sum of its proper divisors (1).

631806421 is an equidigital number, since it uses as much as digits as its factorization.

631806421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6912, while the sum is 31.

The square root of 631806421 is about 25135.7598055042. The cubic root of 631806421 is about 858.0804586734.

The spelling of 631806421 in words is "six hundred thirty-one million, eight hundred six thousand, four hundred twenty-one".