1690221 has 16 divisors (see below), whose sum is σ = 2555840. Its totient is φ = 984960.

The previous prime is 1690219. The next prime is 1690229. The reversal of 1690221 is 1220961.

It is not a de Polignac number, because 1690221 - 2¹ = 1690219 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 (1690229) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 400 + ... + 1881.

It is an arithmetic number, because the mean of its divisors is an integer number (159740).

2^1690221 is an apocalyptic number.

It is an amenable number.

1690221 is a deficient number, since it is larger than the sum of its proper divisors (865619).

1690221 is a wasteful number, since it uses less digits than its factorization.

1690221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2316.

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

The square root of 1690221 is about 1300.0849972213. The cubic root of 1690221 is about 119.1190344352.

The spelling of 1690221 in words is "one million, six hundred ninety thousand, two hundred twenty-one".