20191155 has 16 divisors (see below), whose sum is σ = 34206624. Its totient is φ = 10135040.

The previous prime is 20191151. The next prime is 20191169. The reversal of 20191155 is 55119102.

It is not a de Polignac number, because 20191155 - 2² = 20191151 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20191151) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 39336 + ... + 39845.

It is an arithmetic number, because the mean of its divisors is an integer number (2137914).

Almost surely, 2^20191155 is an apocalyptic number.

20191155 is a deficient number, since it is larger than the sum of its proper divisors (14015469).

20191155 is a wasteful number, since it uses less digits than its factorization.

20191155 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 79206.

The product of its (nonzero) digits is 450, while the sum is 24.

The square root of 20191155 is about 4493.4569097745. The cubic root of 20191155 is about 272.3038118774.

The spelling of 20191155 in words is "twenty million, one hundred ninety-one thousand, one hundred fifty-five".