671649633 has 12 divisors (see below), whose sum is σ = 975087828. Its totient is φ = 445492320.

The previous prime is 671649571. The next prime is 671649673. The reversal of 671649633 is 336946176.

671649633 is a `hidden beast` number, since 6 + 7 + 1 + 6 + 4 + 9 + 633 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 485409024 + 186240609 = 22032^2 + 13647^2 .

It is not a de Polignac number, because 671649633 - 2¹³ = 671641441 is a prime.

It is a super-2 number, since 2×671649633² = 902226459018069378, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (671649673) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 187638 + ... + 191183.

It is an arithmetic number, because the mean of its divisors is an integer number (81257319).

Almost surely, 2^671649633 is an apocalyptic number.

It is an amenable number.

671649633 is a deficient number, since it is larger than the sum of its proper divisors (303438195).

671649633 is a wasteful number, since it uses less digits than its factorization.

671649633 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 379024 (or 379021 counting only the distinct ones).

The product of its digits is 489888, while the sum is 45.

The square root of 671649633 is about 25916.2040623236. The cubic root of 671649633 is about 875.7515754245.

The spelling of 671649633 in words is "six hundred seventy-one million, six hundred forty-nine thousand, six hundred thirty-three".