1921808541 has 8 divisors (see below), whose sum is σ = 2562640864. Its totient is φ = 1281090960.

The previous prime is 1921808531. The next prime is 1921808543. The reversal of 1921808541 is 1458081291.

1921808541 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1921808541 - 2¹⁵ = 1921775773 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1921808541.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1921808543) 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, 24471 + ... + 66651.

It is an arithmetic number, because the mean of its divisors is an integer number (320330108).

Almost surely, 2^1921808541 is an apocalyptic number.

It is an amenable number.

1921808541 is a deficient number, since it is larger than the sum of its proper divisors (640832323).

1921808541 is a wasteful number, since it uses less digits than its factorization.

1921808541 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57371.

The product of its (nonzero) digits is 23040, while the sum is 39.

The square root of 1921808541 is about 43838.4367992291. The cubic root of 1921808541 is about 1243.2831269553.

The spelling of 1921808541 in words is "one billion, nine hundred twenty-one million, eight hundred eight thousand, five hundred forty-one".