1921338144 has 240 divisors, whose sum is σ = 6249640320. Its totient is φ = 574179840.

The previous prime is 1921338071. The next prime is 1921338151. The reversal of 1921338144 is 4418331291.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 1921338099 and 1921338108.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 2252022 + ... + 2252874.

It is an arithmetic number, because the mean of its divisors is an integer number (26040168).

Almost surely, 2^1921338144 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1921338144, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3124820160).

1921338144 is an abundant number, since it is smaller than the sum of its proper divisors (4328302176).

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

1921338144 is a wasteful number, since it uses less digits than its factorization.

1921338144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 965 (or 948 counting only the distinct ones).

The product of its digits is 20736, while the sum is 36.

The square root of 1921338144 is about 43833.0713502944. The cubic root of 1921338144 is about 1243.1816800866.

The spelling of 1921338144 in words is "one billion, nine hundred twenty-one million, three hundred thirty-eight thousand, one hundred forty-four".