1720816 has 20 divisors (see below), whose sum is σ = 3363624. Its totient is φ = 852800.

The previous prime is 1720799. The next prime is 1720843. The reversal of 1720816 is 6180271.

It is a super-2 number, since 2×1720816² = 5922415411712, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1686 + ... + 2506.

2^1720816 is an apocalyptic number.

1720816 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

1720816 is a deficient number, since it is larger than the sum of its proper divisors (1642808).

1720816 is a wasteful number, since it uses less digits than its factorization.

1720816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 960 (or 954 counting only the distinct ones).

The product of its (nonzero) digits is 672, while the sum is 25.

The square root of 1720816 is about 1311.7987650551. The cubic root of 1720816 is about 119.8334727161.

The spelling of 1720816 in words is "one million, seven hundred twenty thousand, eight hundred sixteen".