20101309 has 2 divisors, whose sum is σ = 20101310. Its totient is φ = 20101308.

The previous prime is 20101283. The next prime is 20101331. The reversal of 20101309 is 90310102.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19980900 + 120409 = 4470^2 + 347^2 .

It is a cyclic number.

It is not a de Polignac number, because 20101309 - 2¹⁹ = 19577021 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20101292 and 20101301.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20101349) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10050654 + 10050655.

It is an arithmetic number, because the mean of its divisors is an integer number (10050655).

Almost surely, 2^20101309 is an apocalyptic number.

It is an amenable number.

20101309 is a deficient number, since it is larger than the sum of its proper divisors (1).

20101309 is an equidigital number, since it uses as much as digits as its factorization.

20101309 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 54, while the sum is 16.

The square root of 20101309 is about 4483.4483380541. The cubic root of 20101309 is about 271.8993148465.

The spelling of 20101309 in words is "twenty million, one hundred one thousand, three hundred nine".