1821054823 has 4 divisors (see below), whose sum is σ = 2081205520. Its totient is φ = 1560904128.

The previous prime is 1821054799. The next prime is 1821054839. The reversal of 1821054823 is 3284501281.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3284501281 = 883 ⋅3719707.

It is not a de Polignac number, because 1821054823 - 2¹⁷ = 1820923751 is a prime.

It is a super-2 number, since 2×1821054823² = 6632481336743122658, 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 (1821054223) 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, 130075338 + ... + 130075351.

It is an arithmetic number, because the mean of its divisors is an integer number (520301380).

Almost surely, 2^1821054823 is an apocalyptic number.

1821054823 is a deficient number, since it is larger than the sum of its proper divisors (260150697).

1821054823 is an equidigital number, since it uses as much as digits as its factorization.

1821054823 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 260150696.

The product of its (nonzero) digits is 15360, while the sum is 34.

The square root of 1821054823 is about 42673.8189408916. The cubic root of 1821054823 is about 1221.1649767477.

The spelling of 1821054823 in words is "one billion, eight hundred twenty-one million, fifty-four thousand, eight hundred twenty-three".