1660649081 has 8 divisors (see below), whose sum is σ = 2043875904. Its totient is φ = 1313920080.

The previous prime is 1660649057. The next prime is 1660649093. The reversal of 1660649081 is 1809460661.

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 1660649081 - 2¹⁰ = 1660648057 is a prime.

It is a super-2 number, since 2×1660649081² = 5515510740452289122, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1660649681) 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, 9124355 + ... + 9124536.

It is an arithmetic number, because the mean of its divisors is an integer number (255484488).

Almost surely, 2^1660649081 is an apocalyptic number.

It is an amenable number.

1660649081 is a deficient number, since it is larger than the sum of its proper divisors (383226823).

1660649081 is a wasteful number, since it uses less digits than its factorization.

1660649081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18248911.

The product of its (nonzero) digits is 62208, while the sum is 41.

The square root of 1660649081 is about 40751.0623297111. The cubic root of 1660649081 is about 1184.2024533677.

The spelling of 1660649081 in words is "one billion, six hundred sixty million, six hundred forty-nine thousand, eighty-one".