17139821 has 2 divisors, whose sum is σ = 17139822. Its totient is φ = 17139820.

The previous prime is 17139809. The next prime is 17139827. The reversal of 17139821 is 12893171.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13586596 + 3553225 = 3686^2 + 1885^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-17139821 is a prime.

It is a Chen prime.

It is equal to p_1099724 and since 17139821 and 1099724 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 (17139827) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8569910 + 8569911.

It is an arithmetic number, because the mean of its divisors is an integer number (8569911).

Almost surely, 2^17139821 is an apocalyptic number.

It is an amenable number.

17139821 is a deficient number, since it is larger than the sum of its proper divisors (1).

17139821 is an equidigital number, since it uses as much as digits as its factorization.

17139821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3024, while the sum is 32.

The square root of 17139821 is about 4140.0266907352. The cubic root of 17139821 is about 257.8311747305.

The spelling of 17139821 in words is "seventeen million, one hundred thirty-nine thousand, eight hundred twenty-one".