3633651661 has 4 divisors (see below), whose sum is σ = 3718155232. Its totient is φ = 3549148092.

The previous prime is 3633651647. The next prime is 3633651677. The reversal of 3633651661 is 1661563363.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 3633651661 - 2⁵ = 3633651629 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3633655661) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 42251721 + ... + 42251806.

It is an arithmetic number, because the mean of its divisors is an integer number (929538808).

Almost surely, 2^3633651661 is an apocalyptic number.

It is an amenable number.

3633651661 is a deficient number, since it is larger than the sum of its proper divisors (84503571).

3633651661 is an equidigital number, since it uses as much as digits as its factorization.

3633651661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 84503570.

The product of its digits is 174960, while the sum is 40.

The square root of 3633651661 is about 60279.7782096119. The cubic root of 3633651661 is about 1537.3795404424.

The spelling of 3633651661 in words is "three billion, six hundred thirty-three million, six hundred fifty-one thousand, six hundred sixty-one".