2191421 has 8 divisors (see below), whose sum is σ = 2279424. Its totient is φ = 2104560.

The previous prime is 2191393. The next prime is 2191429. The reversal of 2191421 is 1241912.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2191421 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 2191393 and 2191402.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2191429) 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, 6755 + ... + 7071.

It is an arithmetic number, because the mean of its divisors is an integer number (284928).

2^2191421 is an apocalyptic number.

It is an amenable number.

2191421 is a deficient number, since it is larger than the sum of its proper divisors (88003).

2191421 is a wasteful number, since it uses less digits than its factorization.

2191421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 571.

The product of its digits is 144, while the sum is 20.

The square root of 2191421 is about 1480.3448922464. The cubic root of 2191421 is about 129.8898672769.

The spelling of 2191421 in words is "two million, one hundred ninety-one thousand, four hundred twenty-one".