1606407581 has 8 divisors (see below), whose sum is σ = 1637488440. Its totient is φ = 1575355392.

The previous prime is 1606407557. The next prime is 1606407599. The reversal of 1606407581 is 1857046061.

It can be written as a sum of positive squares in 4 ways, for example, as 994834681 + 611572900 = 31541^2 + 24730^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 1606407581 - 2¹⁴ = 1606391197 is a prime.

It is a super-2 number, since 2×1606407581² = 5161090632588543122, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1606407181) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 131585 + ... + 143273.

It is an arithmetic number, because the mean of its divisors is an integer number (204686055).

Almost surely, 2^1606407581 is an apocalyptic number.

It is an amenable number.

1606407581 is a deficient number, since it is larger than the sum of its proper divisors (31080859).

1606407581 is a wasteful number, since it uses less digits than its factorization.

1606407581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14335.

The product of its (nonzero) digits is 40320, while the sum is 38.

The square root of 1606407581 is about 40080.0147330312. The cubic root of 1606407581 is about 1171.1663390547.

The spelling of 1606407581 in words is "one billion, six hundred six million, four hundred seven thousand, five hundred eighty-one".