1821771340 has 48 divisors (see below), whose sum is σ = 4090945824. Its totient is φ = 679040000.

The previous prime is 1821771307. The next prime is 1821771353. The reversal of 1821771340 is 431771281.

It is a Harshad number since it is a multiple of its sum of digits (34).

It is a junction number, because it is equal to n+sod(n) for n = 1821771296 and 1821771305.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7815 + ... + 60865.

It is an arithmetic number, because the mean of its divisors is an integer number (85228038).

Almost surely, 2^1821771340 is an apocalyptic number.

1821771340 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1821771340, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2045472912).

1821771340 is an abundant number, since it is smaller than the sum of its proper divisors (2269174484).

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

1821771340 is a wasteful number, since it uses less digits than its factorization.

1821771340 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53178 (or 53176 counting only the distinct ones).

The product of its (nonzero) digits is 9408, while the sum is 34.

The square root of 1821771340 is about 42682.2133915288. The cubic root of 1821771340 is about 1221.3251166698.

The spelling of 1821771340 in words is "one billion, eight hundred twenty-one million, seven hundred seventy-one thousand, three hundred forty".