1660016581 has 8 divisors (see below), whose sum is σ = 1722461720. Its totient is φ = 1598496768.

The previous prime is 1660016549. The next prime is 1660016593. The reversal of 1660016581 is 1856100661.

It can be written as a sum of positive squares in 4 ways, for example, as 287980900 + 1372035681 = 16970^2 + 37041^2 .

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 1660016581 - 2⁵ = 1660016549 is a prime.

It is a super-2 number, since 2×1660016581² = 5511310098389859122, 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 (1660016081) 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, 227676 + ... + 234853.

It is an arithmetic number, because the mean of its divisors is an integer number (215307715).

Almost surely, 2^1660016581 is an apocalyptic number.

It is an amenable number.

1660016581 is a deficient number, since it is larger than the sum of its proper divisors (62445139).

1660016581 is an equidigital number, since it uses as much as digits as its factorization.

1660016581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 462663.

The product of its (nonzero) digits is 8640, while the sum is 34.

The square root of 1660016581 is about 40743.3010567381. The cubic root of 1660016581 is about 1184.0520898395.

The spelling of 1660016581 in words is "one billion, six hundred sixty million, sixteen thousand, five hundred eighty-one".