1606378781 has 8 divisors (see below), whose sum is σ = 1866978240. Its totient is φ = 1353558528.

The previous prime is 1606378777. The next prime is 1606378783. The reversal of 1606378781 is 1878736061.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1606378781 - 2² = 1606378777 is a prime.

It is a super-2 number, since 2×1606378781² = 5160905576094091922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1606378783) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1944356 + ... + 1945181.

It is an arithmetic number, because the mean of its divisors is an integer number (233372280).

Almost surely, 2^1606378781 is an apocalyptic number.

It is an amenable number.

1606378781 is a deficient number, since it is larger than the sum of its proper divisors (260599459).

1606378781 is an equidigital number, since it uses as much as digits as its factorization.

1606378781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3889603.

The product of its (nonzero) digits is 338688, while the sum is 47.

The square root of 1606378781 is about 40079.6554501158. The cubic root of 1606378781 is about 1171.1593400439.

The spelling of 1606378781 in words is "one billion, six hundred six million, three hundred seventy-eight thousand, seven hundred eighty-one".