663371381 has 4 divisors (see below), whose sum is σ = 663478764. Its totient is φ = 663264000.

The previous prime is 663371353. The next prime is 663371383. The reversal of 663371381 is 183173366.

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 43112356 + 620259025 = 6566^2 + 24905^2 .

It is a cyclic number.

It is not a de Polignac number, because 663371381 - 2¹⁴ = 663354997 is a prime.

It is a super-2 number, since 2×663371381² = 880123178259694322, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (663371383) 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 in 3 ways as a sum of consecutive naturals, for example, 43820 + ... + 56981.

It is an arithmetic number, because the mean of its divisors is an integer number (165869691).

Almost surely, 2^663371381 is an apocalyptic number.

It is an amenable number.

663371381 is a deficient number, since it is larger than the sum of its proper divisors (107383).

663371381 is a wasteful number, since it uses less digits than its factorization.

663371381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 107382.

The product of its digits is 54432, while the sum is 38.

The square root of 663371381 is about 25755.9969909922. The cubic root of 663371381 is about 872.1387380779.

The spelling of 663371381 in words is "six hundred sixty-three million, three hundred seventy-one thousand, three hundred eighty-one".