2181553091 has 4 divisors (see below), whose sum is σ = 2182998384. Its totient is φ = 2180107800.

The previous prime is 2181553037. The next prime is 2181553123. The reversal of 2181553091 is 1903551812.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 2181553091 - 2²² = 2177358787 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2181553991) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 720380 + ... + 723401.

It is an arithmetic number, because the mean of its divisors is an integer number (545749596).

Almost surely, 2^2181553091 is an apocalyptic number.

2181553091 is a deficient number, since it is larger than the sum of its proper divisors (1445293).

2181553091 is a wasteful number, since it uses less digits than its factorization.

2181553091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1445292.

The product of its (nonzero) digits is 10800, while the sum is 35.

The square root of 2181553091 is about 46707.0989358149. The cubic root of 2181553091 is about 1296.9461039418.

The spelling of 2181553091 in words is "two billion, one hundred eighty-one million, five hundred fifty-three thousand, ninety-one".