1820727121920 has 384 divisors, whose sum is σ = 6707954373120. Its totient is φ = 412982968320.

The previous prime is 1820727121867. The next prime is 1820727121933. The reversal of 1820727121920 is 291217270281.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (384).

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 28137924 + ... + 28202556.

It is an arithmetic number, because the mean of its divisors is an integer number (17468631180).

Almost surely, 2^{1820727121920} is an apocalyptic number.

1820727121920 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 1820727121920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3353977186560).

1820727121920 is an abundant number, since it is smaller than the sum of its proper divisors (4887227251200).

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

1820727121920 is a wasteful number, since it uses less digits than its factorization.

1820727121920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64801 (or 64781 counting only the distinct ones).

The product of its (nonzero) digits is 56448, while the sum is 42.

The spelling of 1820727121920 in words is "one trillion, eight hundred twenty billion, seven hundred twenty-seven million, one hundred twenty-one thousand, nine hundred twenty".