1906221 has 16 divisors (see below), whose sum is σ = 2662400. Its totient is φ = 1211760.

The previous prime is 1906211. The next prime is 1906237. The reversal of 1906221 is 1226091.

It is a de Polignac number, because none of the positive numbers 2^k-1906221 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1906211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9480 + ... + 9678.

It is an arithmetic number, because the mean of its divisors is an integer number (166400).

2^1906221 is an apocalyptic number.

It is an amenable number.

1906221 is a deficient number, since it is larger than the sum of its proper divisors (756179).

1906221 is a wasteful number, since it uses less digits than its factorization.

1906221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 336.

The product of its (nonzero) digits is 216, while the sum is 21.

The square root of 1906221 is about 1380.6596249619. The cubic root of 1906221 is about 123.9912628252.

The spelling of 1906221 in words is "one million, nine hundred six thousand, two hundred twenty-one".