1821681423 has 12 divisors (see below), whose sum is σ = 2631820048. Its totient is φ = 1214222400.

The previous prime is 1821681377. The next prime is 1821681431. The reversal of 1821681423 is 3241861281.

1821681423 is a `hidden beast` number, since 18 + 216 + 8 + 1 + 423 = 666.

1821681423 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 1821681423 - 2¹⁷ = 1821550351 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1821686423) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 40023 + ... + 72423.

Almost surely, 2^1821681423 is an apocalyptic number.

1821681423 is a deficient number, since it is larger than the sum of its proper divisors (810138625).

1821681423 is a wasteful number, since it uses less digits than its factorization.

1821681423 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38654 (or 38651 counting only the distinct ones).

The product of its digits is 18432, while the sum is 36.

The square root of 1821681423 is about 42681.1600474964. The cubic root of 1821681423 is about 1221.3050227288.

The spelling of 1821681423 in words is "one billion, eight hundred twenty-one million, six hundred eighty-one thousand, four hundred twenty-three".