20148809 has 2 divisors, whose sum is σ = 20148810. Its totient is φ = 20148808.

The previous prime is 20148787. The next prime is 20148827. The reversal of 20148809 is 90884102.

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., 12054784 + 8094025 = 3472^2 + 2845^2 .

It is a cyclic number.

It is not a de Polignac number, because 20148809 - 2²⁰ = 19100233 is a prime.

It is a Chen prime.

It is equal to p_1279445 and since 20148809 and 1279445 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (20148829) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10074404 + 10074405.

It is an arithmetic number, because the mean of its divisors is an integer number (10074405).

Almost surely, 2^20148809 is an apocalyptic number.

It is an amenable number.

20148809 is a deficient number, since it is larger than the sum of its proper divisors (1).

20148809 is an equidigital number, since it uses as much as digits as its factorization.

20148809 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4608, while the sum is 32.

The square root of 20148809 is about 4488.7424742348. The cubic root of 20148809 is about 272.1133151350.

The spelling of 20148809 in words is "twenty million, one hundred forty-eight thousand, eight hundred nine".