631920491 has 2 divisors, whose sum is σ = 631920492. Its totient is φ = 631920490.

The previous prime is 631920463. The next prime is 631920517. The reversal of 631920491 is 194029136.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-631920491 is a prime.

It is not a weakly prime, because it can be changed into another prime (631970491) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 315960245 + 315960246.

It is an arithmetic number, because the mean of its divisors is an integer number (315960246).

Almost surely, 2^631920491 is an apocalyptic number.

631920491 is a deficient number, since it is larger than the sum of its proper divisors (1).

631920491 is an equidigital number, since it uses as much as digits as its factorization.

631920491 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 11664, while the sum is 35.

The square root of 631920491 is about 25138.0287811117. The cubic root of 631920491 is about 858.1320965087.

The spelling of 631920491 in words is "six hundred thirty-one million, nine hundred twenty thousand, four hundred ninety-one".