2191955 has 4 divisors (see below), whose sum is σ = 2630352. Its totient is φ = 1753560.

The previous prime is 2191951. The next prime is 2191957. The reversal of 2191955 is 5591912.

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

It is not a de Polignac number, because 2191955 - 2² = 2191951 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2191951) 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, 219191 + ... + 219200.

It is an arithmetic number, because the mean of its divisors is an integer number (657588).

2^2191955 is an apocalyptic number.

2191955 is a deficient number, since it is larger than the sum of its proper divisors (438397).

2191955 is an equidigital number, since it uses as much as digits as its factorization.

2191955 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 438396.

The product of its digits is 4050, while the sum is 32.

The square root of 2191955 is about 1480.5252446345. The cubic root of 2191955 is about 129.9004168330.

The spelling of 2191955 in words is "two million, one hundred ninety-one thousand, nine hundred fifty-five".