1720081 has 4 divisors (see below), whose sum is σ = 1876464. Its totient is φ = 1563700.

The previous prime is 1720063. The next prime is 1720109. The reversal of 1720081 is 1800271.

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: 1800271 = 11 ⋅163661.

It is a cyclic number.

It is not a de Polignac number, because 1720081 - 2⁵ = 1720049 is a prime.

It is a super-2 number, since 2×1720081² = 5917357293122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1720031) 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, 78175 + ... + 78196.

It is an arithmetic number, because the mean of its divisors is an integer number (469116).

2^1720081 is an apocalyptic number.

1720081 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1720081 is a deficient number, since it is larger than the sum of its proper divisors (156383).

1720081 is a wasteful number, since it uses less digits than its factorization.

1720081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 156382.

The product of its (nonzero) digits is 112, while the sum is 19.

The square root of 1720081 is about 1311.5185854573. The cubic root of 1720081 is about 119.8164090778.

The spelling of 1720081 in words is "one million, seven hundred twenty thousand, eighty-one".