1606643331 has 4 divisors (see below), whose sum is σ = 2142191112. Its totient is φ = 1071095552.

The previous prime is 1606643321. The next prime is 1606643333. The reversal of 1606643331 is 1333466061.

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

It is a cyclic number.

It is not a de Polignac number, because 1606643331 - 2⁵ = 1606643299 is a prime.

It is a super-2 number, since 2×1606643331² = 5162605586093551122, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1606643292 and 1606643301.

It is not an unprimeable number, because it can be changed into a prime (1606643333) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 267773886 + ... + 267773891.

It is an arithmetic number, because the mean of its divisors is an integer number (535547778).

Almost surely, 2^1606643331 is an apocalyptic number.

1606643331 is a deficient number, since it is larger than the sum of its proper divisors (535547781).

1606643331 is an equidigital number, since it uses as much as digits as its factorization.

1606643331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 535547780.

The product of its (nonzero) digits is 23328, while the sum is 33.

The square root of 1606643331 is about 40082.9556170700. The cubic root of 1606643331 is about 1171.2236281600.

The spelling of 1606643331 in words is "one billion, six hundred six million, six hundred forty-three thousand, three hundred thirty-one".