3661568491 has 16 divisors (see below), whose sum is σ = 4237470720. Its totient is φ = 3098969280.

The previous prime is 3661568483. The next prime is 3661568531. The reversal of 3661568491 is 1948651663.

It is a cyclic number.

It is not a de Polignac number, because 3661568491 - 2³ = 3661568483 is a prime.

It is not an unprimeable number, because it can be changed into a prime (3661568461) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 501630 + ... + 508876.

It is an arithmetic number, because the mean of its divisors is an integer number (264841920).

Almost surely, 2^3661568491 is an apocalyptic number.

3661568491 is a deficient number, since it is larger than the sum of its proper divisors (575902229).

3661568491 is an equidigital number, since it uses as much as digits as its factorization.

3661568491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8154.

The product of its digits is 933120, while the sum is 49.

The square root of 3661568491 is about 60510.8956387195. The cubic root of 3661568491 is about 1541.3066566600.

The spelling of 3661568491 in words is "three billion, six hundred sixty-one million, five hundred sixty-eight thousand, four hundred ninety-one".