1528721 has 8 divisors (see below), whose sum is σ = 1636800. Its totient is φ = 1423440.

The previous prime is 1528717. The next prime is 1528733. The reversal of 1528721 is 1278251.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1528721 - 2² = 1528717 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1528771) 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 7 ways as a sum of consecutive naturals, for example, 500 + ... + 1818.

It is an arithmetic number, because the mean of its divisors is an integer number (204600).

2^1528721 is an apocalyptic number.

It is an amenable number.

1528721 is a deficient number, since it is larger than the sum of its proper divisors (108079).

1528721 is a wasteful number, since it uses less digits than its factorization.

1528721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1399.

The product of its digits is 1120, while the sum is 26.

The square root of 1528721 is about 1236.4145744854. The cubic root of 1528721 is about 115.1974176778.

The spelling of 1528721 in words is "one million, five hundred twenty-eight thousand, seven hundred twenty-one".