2191428 has 48 divisors (see below), whose sum is σ = 5765760. Its totient is φ = 719712.

The previous prime is 2191393. The next prime is 2191429. The reversal of 2191428 is 8241912.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (2191429) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11026 + ... + 11222.

It is an arithmetic number, because the mean of its divisors is an integer number (120120).

2^2191428 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2191428, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2882880).

2191428 is an abundant number, since it is smaller than the sum of its proper divisors (3574332).

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

2191428 is a wasteful number, since it uses less digits than its factorization.

2191428 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 313 (or 305 counting only the distinct ones).

The product of its digits is 1152, while the sum is 27.

The square root of 2191428 is about 1480.3472565584. The cubic root of 2191428 is about 129.8900055781.

The spelling of 2191428 in words is "two million, one hundred ninety-one thousand, four hundred twenty-eight".