631409332381 has 2 divisors, whose sum is σ = 631409332382. Its totient is φ = 631409332380.

The previous prime is 631409332373. The next prime is 631409332457. The reversal of 631409332381 is 183233904136.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 554926664356 + 76482668025 = 744934^2 + 276555^2 .

It is a cyclic number.

It is not a de Polignac number, because 631409332381 - 2³ = 631409332373 is a prime.

It is a super-2 number, since 2×631409332381² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (631409332331) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 315704666190 + 315704666191.

It is an arithmetic number, because the mean of its divisors is an integer number (315704666191).

Almost surely, 2^631409332381 is an apocalyptic number.

It is an amenable number.

631409332381 is a deficient number, since it is larger than the sum of its proper divisors (1).

631409332381 is an equidigital number, since it uses as much as digits as its factorization.

631409332381 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 279936, while the sum is 43.

The spelling of 631409332381 in words is "six hundred thirty-one billion, four hundred nine million, three hundred thirty-two thousand, three hundred eighty-one".