20807670209 has 2 divisors, whose sum is σ = 20807670210. Its totient is φ = 20807670208.

The previous prime is 20807670193. The next prime is 20807670223. The reversal of 20807670209 is 90207670802.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20661187600 + 146482609 = 143740^2 + 12103^2 .

It is a cyclic number.

It is not a de Polignac number, because 20807670209 - 2⁴ = 20807670193 is a prime.

It is a super-2 number, since 2×20807670209² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (20807670229) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10403835104 + 10403835105.

It is an arithmetic number, because the mean of its divisors is an integer number (10403835105).

Almost surely, 2^20807670209 is an apocalyptic number.

It is an amenable number.

20807670209 is a deficient number, since it is larger than the sum of its proper divisors (1).

20807670209 is an equidigital number, since it uses as much as digits as its factorization.

20807670209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 84672, while the sum is 41.

The spelling of 20807670209 in words is "twenty billion, eight hundred seven million, six hundred seventy thousand, two hundred nine".