1921181536 has 48 divisors (see below), whose sum is σ = 3951763200. Its totient is φ = 917665408.

The previous prime is 1921181533. The next prime is 1921181573. The reversal of 1921181536 is 6351811291.

It is a junction number, because it is equal to n+sod(n) for n = 1921181495 and 1921181504.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1921181533) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 969795 + ... + 971773.

It is an arithmetic number, because the mean of its divisors is an integer number (82328400).

Almost surely, 2^1921181536 is an apocalyptic number.

1921181536 is a gapful number since it is divisible by the number (16) 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 1921181536, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1975881600).

1921181536 is an abundant number, since it is smaller than the sum of its proper divisors (2030581664).

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

1921181536 is a wasteful number, since it uses less digits than its factorization.

1921181536 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3331 (or 3323 counting only the distinct ones).

The product of its digits is 12960, while the sum is 37.

The square root of 1921181536 is about 43831.2849001715. The cubic root of 1921181536 is about 1243.1479019813.

The spelling of 1921181536 in words is "one billion, nine hundred twenty-one million, one hundred eighty-one thousand, five hundred thirty-six".