1821851648 has 120 divisors (see below), whose sum is σ = 4001243904. Its totient is φ = 825753600.

The previous prime is 1821851641. The next prime is 1821851663. The reversal of 1821851648 is 8461581281.

It is a Smith number, since the sum of its digits (44) coincides with the sum of the digits of its prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 1821851599 and 1821851608.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1821851641) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8634263 + ... + 8634473.

Almost surely, 2^1821851648 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1821851648, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2000621952).

1821851648 is an abundant number, since it is smaller than the sum of its proper divisors (2179392256).

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

1821851648 is an equidigital number, since it uses as much as digits as its factorization.

1821851648 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 287 (or 261 counting only the distinct ones).

The product of its digits is 122880, while the sum is 44.

The square root of 1821851648 is about 42683.1541477431. The cubic root of 1821851648 is about 1221.3430627084.

The spelling of 1821851648 in words is "one billion, eight hundred twenty-one million, eight hundred fifty-one thousand, six hundred forty-eight".