1566650661 has 8 divisors (see below), whose sum is σ = 2089078464. Its totient is φ = 1044328320.

The previous prime is 1566650653. The next prime is 1566650663. The reversal of 1566650661 is 1660566651.

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

It is not a de Polignac number, because 1566650661 - 2³ = 1566650653 is a prime.

It is a super-2 number, since 2×1566650661² = 4908788587223473842, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1566650663) 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, 19896 + ... + 59406.

It is an arithmetic number, because the mean of its divisors is an integer number (261134808).

Almost surely, 2^1566650661 is an apocalyptic number.

It is an amenable number.

1566650661 is a deficient number, since it is larger than the sum of its proper divisors (522427803).

1566650661 is a wasteful number, since it uses less digits than its factorization.

1566650661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52731.

The product of its (nonzero) digits is 194400, while the sum is 42.

The square root of 1566650661 is about 39580.9381015660. The cubic root of 1566650661 is about 1161.4238018769.

The spelling of 1566650661 in words is "one billion, five hundred sixty-six million, six hundred fifty thousand, six hundred sixty-one".