20064630661 has 4 divisors (see below), whose sum is σ = 20443208652. Its totient is φ = 19686052672.

The previous prime is 20064630637. The next prime is 20064630671. The reversal of 20064630661 is 16603646002.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 16603646002 = 2 ⋅8301823001.

It can be written as a sum of positive squares in 2 ways, for example, as 11060518561 + 9004112100 = 105169^2 + 94890^2 .

It is a cyclic number.

It is not a de Polignac number, because 20064630661 - 2⁹ = 20064630149 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 (20064630671) 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, 189288916 + ... + 189289021.

It is an arithmetic number, because the mean of its divisors is an integer number (5110802163).

Almost surely, 2^20064630661 is an apocalyptic number.

It is an amenable number.

20064630661 is a deficient number, since it is larger than the sum of its proper divisors (378577991).

20064630661 is an equidigital number, since it uses as much as digits as its factorization.

20064630661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 378577990.

The product of its (nonzero) digits is 31104, while the sum is 34.

The spelling of 20064630661 in words is "twenty billion, sixty-four million, six hundred thirty thousand, six hundred sixty-one".