20139499 has 2 divisors, whose sum is σ = 20139500. Its totient is φ = 20139498.

The previous prime is 20139481. The next prime is 20139503. The reversal of 20139499 is 99493102.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20139499 is a prime.

It is not a weakly prime, because it can be changed into another prime (20139409) by changing a digit.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10069749 + 10069750.

It is an arithmetic number, because the mean of its divisors is an integer number (10069750).

Almost surely, 2^20139499 is an apocalyptic number.

20139499 is a deficient number, since it is larger than the sum of its proper divisors (1).

20139499 is an equidigital number, since it uses as much as digits as its factorization.

20139499 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 17496, while the sum is 37.

The square root of 20139499 is about 4487.7053156374. The cubic root of 20139499 is about 272.0713975994.

The spelling of 20139499 in words is "twenty million, one hundred thirty-nine thousand, four hundred ninety-nine".