1920001820 has 96 divisors (see below), whose sum is σ = 4604705280. Its totient is φ = 665660160.

The previous prime is 1920001807. The next prime is 1920001823. The reversal of 1920001820 is 281000291.

It is a Harshad number since it is a multiple of its sum of digits (23).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1920001823) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3101471 + ... + 3102089.

It is an arithmetic number, because the mean of its divisors is an integer number (47965680).

Almost surely, 2^1920001820 is an apocalyptic number.

1920001820 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 1920001820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2302352640).

1920001820 is an abundant number, since it is smaller than the sum of its proper divisors (2684703460).

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

1920001820 is a wasteful number, since it uses less digits than its factorization.

1920001820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1275 (or 1273 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 23.

The square root of 1920001820 is about 43817.8253682220. The cubic root of 1920001820 is about 1242.8933951011.

The spelling of 1920001820 in words is "one billion, nine hundred twenty million, one thousand, eight hundred twenty".