20423449 has 2 divisors, whose sum is σ = 20423450. Its totient is φ = 20423448.

The previous prime is 20423441. The next prime is 20423479. The reversal of 20423449 is 94432402.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18983449 + 1440000 = 4357^2 + 1200^2 .

It is a cyclic number.

It is not a de Polignac number, because 20423449 - 2³ = 20423441 is a prime.

It is not a weakly prime, because it can be changed into another prime (20423441) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10211724 + 10211725.

It is an arithmetic number, because the mean of its divisors is an integer number (10211725).

Almost surely, 2^20423449 is an apocalyptic number.

It is an amenable number.

20423449 is a deficient number, since it is larger than the sum of its proper divisors (1).

20423449 is an equidigital number, since it uses as much as digits as its factorization.

20423449 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6912, while the sum is 28.

The square root of 20423449 is about 4519.2310186579. The cubic root of 20423449 is about 273.3440941960.

It can be divided in two parts, 204 and 23449, that added together give a triangular number (23653 = T₂₁₇).

The spelling of 20423449 in words is "twenty million, four hundred twenty-three thousand, four hundred forty-nine".