1816821774 has 24 divisors (see below), whose sum is σ = 4063430592. Its totient is φ = 586071360.

The previous prime is 1816821761. The next prime is 1816821791. The reversal of 1816821774 is 4771286181.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

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, 1627419 + ... + 1628534.

It is an arithmetic number, because the mean of its divisors is an integer number (169309608).

Almost surely, 2^1816821774 is an apocalyptic number.

1816821774 is an abundant number, since it is smaller than the sum of its proper divisors (2246608818).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1816821774 is a wasteful number, since it uses less digits than its factorization.

1816821774 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3255992 (or 3255989 counting only the distinct ones).

The product of its digits is 150528, while the sum is 45.

The square root of 1816821774 is about 42624.1923559849. The cubic root of 1816821774 is about 1220.2180417417.

The spelling of 1816821774 in words is "one billion, eight hundred sixteen million, eight hundred twenty-one thousand, seven hundred seventy-four".