1870721 has 4 divisors (see below), whose sum is σ = 1969200. Its totient is φ = 1772244.

The previous prime is 1870717. The next prime is 1870723. The reversal of 1870721 is 1270781.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1270781 = 53 ⋅23977.

It is not a de Polignac number, because 1870721 - 2² = 1870717 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1870723) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 49211 + ... + 49248.

It is an arithmetic number, because the mean of its divisors is an integer number (492300).

2^1870721 is an apocalyptic number.

It is an amenable number.

1870721 is a deficient number, since it is larger than the sum of its proper divisors (98479).

1870721 is an equidigital number, since it uses as much as digits as its factorization.

1870721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 98478.

The product of its (nonzero) digits is 784, while the sum is 26.

The square root of 1870721 is about 1367.7430314207. The cubic root of 1870721 is about 123.2167285220.

The spelling of 1870721 in words is "one million, eight hundred seventy thousand, seven hundred twenty-one".