3561621666 has 8 divisors (see below), whose sum is σ = 7123243344. Its totient is φ = 1187207220.

The previous prime is 3561621647. The next prime is 3561621683. The reversal of 3561621666 is 6661261653.

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

3561621666 is an admirable number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 296801800 + ... + 296801811.

It is an arithmetic number, because the mean of its divisors is an integer number (890405418).

Almost surely, 2^3561621666 is an apocalyptic number.

3561621666 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

3561621666 is a wasteful number, since it uses less digits than its factorization.

3561621666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 593603616.

The product of its digits is 233280, while the sum is 42.

The square root of 3561621666 is about 59679.3236054163. The cubic root of 3561621666 is about 1527.1531589558.

The spelling of 3561621666 in words is "three billion, five hundred sixty-one million, six hundred twenty-one thousand, six hundred sixty-six".