20209493 has 2 divisors, whose sum is σ = 20209494. Its totient is φ = 20209492.

The previous prime is 20209477. The next prime is 20209523. The reversal of 20209493 is 39490202.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16056049 + 4153444 = 4007^2 + 2038^2 .

It is a cyclic number.

It is not a de Polignac number, because 20209493 - 2⁴ = 20209477 is a prime.

It is a Chen prime.

It is equal to p_1283069 and since 20209493 and 1283069 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20209993) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10104746 + 10104747.

It is an arithmetic number, because the mean of its divisors is an integer number (10104747).

Almost surely, 2^20209493 is an apocalyptic number.

It is an amenable number.

20209493 is a deficient number, since it is larger than the sum of its proper divisors (1).

20209493 is an equidigital number, since it uses as much as digits as its factorization.

20209493 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3888, while the sum is 29.

The square root of 20209493 is about 4495.4969691904. The cubic root of 20209493 is about 272.3862241404.

Adding to 20209493 its reverse (39490202), we get a palindrome (59699695).

It can be divided in two parts, 20209 and 493, that added together give a palindrome (20702).

The spelling of 20209493 in words is "twenty million, two hundred nine thousand, four hundred ninety-three".