1821928680 has 512 divisors, whose sum is σ = 7315660800. Its totient is φ = 397440000.

The previous prime is 1821928651. The next prime is 1821928687. The reversal of 1821928680 is 868291281.

It is a happy number.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (1821928687) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 7258555 + ... + 7258805.

It is an arithmetic number, because the mean of its divisors is an integer number (14288400).

Almost surely, 2^1821928680 is an apocalyptic number.

1821928680 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 1821928680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3657830400).

1821928680 is an abundant number, since it is smaller than the sum of its proper divisors (5493732120).

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

1821928680 is a wasteful number, since it uses less digits than its factorization.

1821928680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 342 (or 332 counting only the distinct ones).

The product of its (nonzero) digits is 110592, while the sum is 45.

The square root of 1821928680 is about 42684.0565082561. The cubic root of 1821928680 is about 1221.3602761796.

The spelling of 1821928680 in words is "one billion, eight hundred twenty-one million, nine hundred twenty-eight thousand, six hundred eighty".