1527721 has 4 divisors (see below), whose sum is σ = 1645252. Its totient is φ = 1410192.

The previous prime is 1527709. The next prime is 1527727. The reversal of 1527721 is 1277251.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1277251 = 137 ⋅9323.

It can be written as a sum of positive squares in 2 ways, for example, as 230400 + 1297321 = 480^2 + 1139^2 .

It is a cyclic number.

It is not a de Polignac number, because 1527721 - 2⁵ = 1527689 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1527727) 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 3 ways as a sum of consecutive naturals, for example, 58746 + ... + 58771.

It is an arithmetic number, because the mean of its divisors is an integer number (411313).

2^1527721 is an apocalyptic number.

It is an amenable number.

1527721 is a deficient number, since it is larger than the sum of its proper divisors (117531).

1527721 is a wasteful number, since it uses less digits than its factorization.

1527721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 117530.

The product of its digits is 980, while the sum is 25.

The square root of 1527721 is about 1236.0101132272. The cubic root of 1527721 is about 115.1722937244.

Subtracting from 1527721 its sum of digits (25), we obtain a square (1527696 = 1236²).

The spelling of 1527721 in words is "one million, five hundred twenty-seven thousand, seven hundred twenty-one".