1720836 has 36 divisors (see below), whose sum is σ = 4685772. Its totient is φ = 529344.

The previous prime is 1720799. The next prime is 1720843. The reversal of 1720836 is 6380271.

It can be written as a sum of positive squares in 2 ways, for example, as 799236 + 921600 = 894^2 + 960^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a super-2 number, since 2×1720836² = 5922553077792, 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 11 ways as a sum of consecutive naturals, for example, 1371 + ... + 2306.

2^1720836 is an apocalyptic number.

It is an amenable number.

1720836 is an abundant number, since it is smaller than the sum of its proper divisors (2964936).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1720836 is a wasteful number, since it uses less digits than its factorization.

1720836 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3700 (or 3695 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 27.

The square root of 1720836 is about 1311.8063881534. The cubic root of 1720836 is about 119.8339369649.

It can be divided in two parts, 1720 and 836, that added together give a triangular number (2556 = T₇₁).

The spelling of 1720836 in words is "one million, seven hundred twenty thousand, eight hundred thirty-six".