663521899 has 2 divisors, whose sum is σ = 663521900. Its totient is φ = 663521898.

The previous prime is 663521897. The next prime is 663521977. The reversal of 663521899 is 998125366.

663521899 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 663521899 - 2¹ = 663521897 is a prime.

It is a super-2 number, since 2×663521899² = 880522620905132402, which contains 22 as substring.

Together with 663521897, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (663521891) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 331760949 + 331760950.

It is an arithmetic number, because the mean of its divisors is an integer number (331760950).

Almost surely, 2^663521899 is an apocalyptic number.

663521899 is a deficient number, since it is larger than the sum of its proper divisors (1).

663521899 is an equidigital number, since it uses as much as digits as its factorization.

663521899 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 699840, while the sum is 49.

The square root of 663521899 is about 25758.9188243606. The cubic root of 663521899 is about 872.2046954260.

The spelling of 663521899 in words is "six hundred sixty-three million, five hundred twenty-one thousand, eight hundred ninety-nine".