671821623 has 24 divisors (see below), whose sum is σ = 1120903056. Its totient is φ = 383212800.

The previous prime is 671821597. The next prime is 671821639. The reversal of 671821623 is 326128176.

671821623 is a `hidden beast` number, since 6 + 7 + 1 + 8 + 21 + 623 = 666.

671821623 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 671821623 - 2¹² = 671817527 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (671821643) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 197908 + ... + 201273.

It is an arithmetic number, because the mean of its divisors is an integer number (46704294).

Almost surely, 2^671821623 is an apocalyptic number.

671821623 is a deficient number, since it is larger than the sum of its proper divisors (449081433).

671821623 is a wasteful number, since it uses less digits than its factorization.

671821623 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 399215 (or 399212 counting only the distinct ones).

The product of its digits is 24192, while the sum is 36.

The square root of 671821623 is about 25919.5220442044. The cubic root of 671821623 is about 875.8263205751.

Adding to 671821623 its reverse (326128176), we get a palindrome (997949799).

The spelling of 671821623 in words is "six hundred seventy-one million, eight hundred twenty-one thousand, six hundred twenty-three".