19639157 has 2 divisors, whose sum is σ = 19639158. Its totient is φ = 19639156.

The previous prime is 19639121. The next prime is 19639181. The reversal of 19639157 is 75193691.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 9991921 + 9647236 = 3161^2 + 3106^2 .

It is an emirp because it is prime and its reverse (75193691) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 19639157 - 2⁸ = 19638901 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19639057) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9819578 + 9819579.

It is an arithmetic number, because the mean of its divisors is an integer number (9819579).

Almost surely, 2^19639157 is an apocalyptic number.

It is an amenable number.

19639157 is a deficient number, since it is larger than the sum of its proper divisors (1).

19639157 is an equidigital number, since it uses as much as digits as its factorization.

19639157 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 51030, while the sum is 41.

The square root of 19639157 is about 4431.6088500679. The cubic root of 19639157 is about 269.7993800040.

The spelling of 19639157 in words is "nineteen million, six hundred thirty-nine thousand, one hundred fifty-seven".