663378829 has 4 divisors (see below), whose sum is σ = 670217884. Its totient is φ = 656539776.

The previous prime is 663378823. The next prime is 663378841. The reversal of 663378829 is 928873366.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 191185929 + 472192900 = 13827^2 + 21730^2 .

It is a cyclic number.

It is not a de Polignac number, because 663378829 - 2⁷ = 663378701 is a prime.

It is a super-2 number, since 2×663378829² = 880142941530822482, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (663378823) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3419382 + ... + 3419575.

It is an arithmetic number, because the mean of its divisors is an integer number (167554471).

Almost surely, 2^663378829 is an apocalyptic number.

It is an amenable number.

663378829 is a deficient number, since it is larger than the sum of its proper divisors (6839055).

663378829 is an equidigital number, since it uses as much as digits as its factorization.

663378829 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6839054.

The product of its digits is 2612736, while the sum is 52.

The square root of 663378829 is about 25756.1415782722. The cubic root of 663378829 is about 872.1420020440.

The spelling of 663378829 in words is "six hundred sixty-three million, three hundred seventy-eight thousand, eight hundred twenty-nine".