63919991 has 2 divisors, whose sum is σ = 63919992. Its totient is φ = 63919990.

The previous prime is 63919963. The next prime is 63920011. The reversal of 63919991 is 19991936.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 63919991 - 2¹⁴ = 63903607 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (63919931) 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, 31959995 + 31959996.

It is an arithmetic number, because the mean of its divisors is an integer number (31959996).

Almost surely, 2^63919991 is an apocalyptic number.

63919991 is a deficient number, since it is larger than the sum of its proper divisors (1).

63919991 is an equidigital number, since it uses as much as digits as its factorization.

63919991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 118098, while the sum is 47.

The square root of 63919991 is about 7994.9978736708. The cubic root of 63919991 is about 399.8332450750.

The spelling of 63919991 in words is "sixty-three million, nine hundred nineteen thousand, nine hundred ninety-one".