20102566109 has 2 divisors, whose sum is σ = 20102566110. Its totient is φ = 20102566108.

The previous prime is 20102566069. The next prime is 20102566123. The reversal of 20102566109 is 90166520102.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10841390884 + 9261175225 = 104122^2 + 96235^2 .

It is a cyclic number.

It is not a de Polignac number, because 20102566109 - 2⁸ = 20102565853 is a prime.

It is a super-2 number, since 2×20102566109² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20102566129) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10051283054 + 10051283055.

It is an arithmetic number, because the mean of its divisors is an integer number (10051283055).

Almost surely, 2^20102566109 is an apocalyptic number.

It is an amenable number.

20102566109 is a deficient number, since it is larger than the sum of its proper divisors (1).

20102566109 is an equidigital number, since it uses as much as digits as its factorization.

20102566109 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6480, while the sum is 32.

The spelling of 20102566109 in words is "twenty billion, one hundred two million, five hundred sixty-six thousand, one hundred nine".