2187491 has 2 divisors, whose sum is σ = 2187492. Its totient is φ = 2187490.

The previous prime is 2187463. The next prime is 2187511. The reversal of 2187491 is 1947812.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 2187491 - 2¹⁰ = 2186467 is a prime.

It is not a weakly prime, because it can be changed into another prime (2187421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1093745 + 1093746.

It is an arithmetic number, because the mean of its divisors is an integer number (1093746).

2^2187491 is an apocalyptic number.

2187491 is a deficient number, since it is larger than the sum of its proper divisors (1).

2187491 is an equidigital number, since it uses as much as digits as its factorization.

2187491 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4032, while the sum is 32.

The square root of 2187491 is about 1479.0169032165. The cubic root of 2187491 is about 129.8121745177.

The spelling of 2187491 in words is "two million, one hundred eighty-seven thousand, four hundred ninety-one".