1720539 has 12 divisors (see below), whose sum is σ = 2532816. Its totient is φ = 1125072.

The previous prime is 1720517. The next prime is 1720549. The reversal of 1720539 is 9350271.

It is not a de Polignac number, because 1720539 - 2¹² = 1716443 is a prime.

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

1720539 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (1720549) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1327 + ... + 2280.

It is an arithmetic number, because the mean of its divisors is an integer number (211068).

2^1720539 is an apocalyptic number.

1720539 is a deficient number, since it is larger than the sum of its proper divisors (812277).

1720539 is a wasteful number, since it uses less digits than its factorization.

1720539 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3666 (or 3663 counting only the distinct ones).

The product of its (nonzero) digits is 1890, while the sum is 27.

The square root of 1720539 is about 1311.6931805876. The cubic root of 1720539 is about 119.8270425006.

The spelling of 1720539 in words is "one million, seven hundred twenty thousand, five hundred thirty-nine".