1889721 has 24 divisors (see below), whose sum is σ = 2951520. Its totient is φ = 1161216.

The previous prime is 1889717. The next prime is 1889743. The reversal of 1889721 is 1279881.

It is not a de Polignac number, because 1889721 - 2² = 1889717 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1889761) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 7225 + ... + 7481.

It is an arithmetic number, because the mean of its divisors is an integer number (122980).

2^1889721 is an apocalyptic number.

It is an amenable number.

1889721 is a deficient number, since it is larger than the sum of its proper divisors (1061799).

1889721 is a wasteful number, since it uses less digits than its factorization.

1889721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 325 (or 322 counting only the distinct ones).

The product of its digits is 8064, while the sum is 36.

The square root of 1889721 is about 1374.6712334227. The cubic root of 1889721 is about 123.6324748928.

The spelling of 1889721 in words is "one million, eight hundred eighty-nine thousand, seven hundred twenty-one".