1919389440 has 144 divisors (see below), whose sum is σ = 6194448288. Its totient is φ = 506462208.

The previous prime is 1919389391. The next prime is 1919389463. The reversal of 1919389440 is 449839191.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a self number, because there is not a number n which added to its sum of digits gives 1919389440.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 369904 + ... + 375056.

It is an arithmetic number, because the mean of its divisors is an integer number (43017002).

Almost surely, 2^1919389440 is an apocalyptic number.

1919389440 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 1919389440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3097224144).

1919389440 is an abundant number, since it is smaller than the sum of its proper divisors (4275058848).

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

1919389440 is an equidigital number, since it uses as much as digits as its factorization.

1919389440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5274 (or 5260 counting only the distinct ones).

The product of its (nonzero) digits is 279936, while the sum is 48.

The square root of 1919389440 is about 43810.8370155148. The cubic root of 1919389440 is about 1242.7612417557.

The spelling of 1919389440 in words is "one billion, nine hundred nineteen million, three hundred eighty-nine thousand, four hundred forty".