20466449921 has 2 divisors, whose sum is σ = 20466449922. Its totient is φ = 20466449920.

The previous prime is 20466449903. The next prime is 20466449959. The reversal of 20466449921 is 12994466402.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17151569296 + 3314880625 = 130964^2 + 57575^2 .

It is a cyclic number.

It is not a de Polignac number, because 20466449921 - 2¹⁰ = 20466448897 is a prime.

It is not a weakly prime, because it can be changed into another prime (20466442921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10233224960 + 10233224961.

It is an arithmetic number, because the mean of its divisors is an integer number (10233224961).

Almost surely, 2^20466449921 is an apocalyptic number.

It is an amenable number.

20466449921 is a deficient number, since it is larger than the sum of its proper divisors (1).

20466449921 is an equidigital number, since it uses as much as digits as its factorization.

20466449921 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 746496, while the sum is 47.

The spelling of 20466449921 in words is "twenty billion, four hundred sixty-six million, four hundred forty-nine thousand, nine hundred twenty-one".