1918868820 has 144 divisors (see below), whose sum is σ = 5960485440. Its totient is φ = 460866560.

The previous prime is 1918868807. The next prime is 1918868827. The reversal of 1918868820 is 288688191.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1918868827) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 819211 + ... + 821549.

It is an arithmetic number, because the mean of its divisors is an integer number (41392260).

Almost surely, 2^1918868820 is an apocalyptic number.

1918868820 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 1918868820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2980242720).

1918868820 is an abundant number, since it is smaller than the sum of its proper divisors (4041616620).

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

1918868820 is a wasteful number, since it uses less digits than its factorization.

1918868820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2486 (or 2473 counting only the distinct ones).

The product of its (nonzero) digits is 442368, while the sum is 51.

The square root of 1918868820 is about 43804.8949319594. The cubic root of 1918868820 is about 1242.6488683708.

The spelling of 1918868820 in words is "one billion, nine hundred eighteen million, eight hundred sixty-eight thousand, eight hundred twenty".