20494139 has 2 divisors, whose sum is σ = 20494140. Its totient is φ = 20494138.

The previous prime is 20494051. The next prime is 20494147. The reversal of 20494139 is 93149402.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20494139 is a prime.

It is not a weakly prime, because it can be changed into another prime (20494739) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10247069 + 10247070.

It is an arithmetic number, because the mean of its divisors is an integer number (10247070).

Almost surely, 2^20494139 is an apocalyptic number.

20494139 is a deficient number, since it is larger than the sum of its proper divisors (1).

20494139 is an equidigital number, since it uses as much as digits as its factorization.

20494139 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7776, while the sum is 32.

The square root of 20494139 is about 4527.0452836260. The cubic root of 20494139 is about 273.6590988333.

The spelling of 20494139 in words is "twenty million, four hundred ninety-four thousand, one hundred thirty-nine".