20640217201 has 2 divisors, whose sum is σ = 20640217202. Its totient is φ = 20640217200.

The previous prime is 20640217163. The next prime is 20640217211. The reversal of 20640217201 is 10271204602.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20232217600 + 407999601 = 142240^2 + 20199^2 .

It is a cyclic number.

It is not a de Polignac number, because 20640217201 - 2²⁷ = 20505999473 is a prime.

It is a super-2 number, since 2×20640217201² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (20640217211) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10320108600 + 10320108601.

It is an arithmetic number, because the mean of its divisors is an integer number (10320108601).

Almost surely, 2^20640217201 is an apocalyptic number.

It is an amenable number.

20640217201 is a deficient number, since it is larger than the sum of its proper divisors (1).

20640217201 is an equidigital number, since it uses as much as digits as its factorization.

20640217201 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1344, while the sum is 25.

The spelling of 20640217201 in words is "twenty billion, six hundred forty million, two hundred seventeen thousand, two hundred one".