20216864973709 has 2 divisors, whose sum is σ = 20216864973710. Its totient is φ = 20216864973708.

The previous prime is 20216864973677. The next prime is 20216864973751. The reversal of 20216864973709 is 90737946861202.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19330531222500 + 886333751209 = 4396650^2 + 941453^2 .

It is a cyclic number.

It is not a de Polignac number, because 20216864973709 - 2⁵ = 20216864973677 is a prime.

It is a super-2 number, since 2×20216864973709² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20216864973769) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10108432486854 + 10108432486855.

It is an arithmetic number, because the mean of its divisors is an integer number (10108432486855).

Almost surely, 2^{20216864973709} is an apocalyptic number.

It is an amenable number.

20216864973709 is a deficient number, since it is larger than the sum of its proper divisors (1).

20216864973709 is an equidigital number, since it uses as much as digits as its factorization.

20216864973709 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 54867456, while the sum is 64.

The spelling of 20216864973709 in words is "twenty trillion, two hundred sixteen billion, eight hundred sixty-four million, nine hundred seventy-three thousand, seven hundred nine".