1500721 has 4 divisors (see below), whose sum is σ = 1552500. Its totient is φ = 1448944.

The previous prime is 1500713. The next prime is 1500731. The reversal of 1500721 is 1270051.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 921600 + 579121 = 960^2 + 761^2 .

It is a cyclic number.

It is not a de Polignac number, because 1500721 - 2³ = 1500713 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1500695 and 1500704.

It is not an unprimeable number, because it can be changed into a prime (1500701) 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 3 ways as a sum of consecutive naturals, for example, 25846 + ... + 25903.

It is an arithmetic number, because the mean of its divisors is an integer number (388125).

2^1500721 is an apocalyptic number.

It is an amenable number.

1500721 is a deficient number, since it is larger than the sum of its proper divisors (51779).

1500721 is an equidigital number, since it uses as much as digits as its factorization.

1500721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51778.

The product of its (nonzero) digits is 70, while the sum is 16.

The square root of 1500721 is about 1225.0391830468. The cubic root of 1500721 is about 114.4897621835.

Adding to 1500721 its reverse (1270051), we get a palindrome (2770772).

The spelling of 1500721 in words is "one million, five hundred thousand, seven hundred twenty-one".