1806685646 has 4 divisors (see below), whose sum is σ = 2710028472. Its totient is φ = 903342822.

The previous prime is 1806685633. The next prime is 1806685649. The reversal of 1806685646 is 6465866081.

It is a semiprime because it is the product of two primes.

It is a super-2 number, since 2×1806685646² = 6528226046924874632, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1806685594 and 1806685603.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1806685649) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 451671410 + ... + 451671413.

It is an arithmetic number, because the mean of its divisors is an integer number (677507118).

Almost surely, 2^1806685646 is an apocalyptic number.

1806685646 is a deficient number, since it is larger than the sum of its proper divisors (903342826).

1806685646 is an equidigital number, since it uses as much as digits as its factorization.

1806685646 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 903342825.

The product of its (nonzero) digits is 1658880, while the sum is 50.

The square root of 1806685646 is about 42505.1249380589. The cubic root of 1806685646 is about 1217.9445920170.

It can be divided in two parts, 180668 and 5646, that multiplied together give a triangular number (1020051528 = T₄₅₁₆₇).

The spelling of 1806685646 in words is "one billion, eight hundred six million, six hundred eighty-five thousand, six hundred forty-six".