20666665153 has 4 divisors (see below), whose sum is σ = 20676230788. Its totient is φ = 20657099520.

The previous prime is 20666665133. The next prime is 20666665177. The reversal of 20666665153 is 35156666602.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 13798731024 + 6867934129 = 117468^2 + 82873^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20666665153 is a prime.

It is a super-2 number, since 2×20666665153² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20666665133) 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, 4779576 + ... + 4783897.

It is an arithmetic number, because the mean of its divisors is an integer number (5169057697).

Almost surely, 2^20666665153 is an apocalyptic number.

It is an amenable number.

20666665153 is a deficient number, since it is larger than the sum of its proper divisors (9565635).

20666665153 is an equidigital number, since it uses as much as digits as its factorization.

20666665153 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9565634.

The product of its (nonzero) digits is 1166400, while the sum is 46.

The spelling of 20666665153 in words is "twenty billion, six hundred sixty-six million, six hundred sixty-five thousand, one hundred fifty-three".