19993157 has 2 divisors, whose sum is σ = 19993158. Its totient is φ = 19993156.

The previous prime is 19993097. The next prime is 19993201. The reversal of 19993157 is 75139991.

It is an a-pointer prime, because the next prime (19993201) can be obtained adding 19993157 to its sum of digits (44).

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11519236 + 8473921 = 3394^2 + 2911^2 .

It is a cyclic number.

It is not a de Polignac number, because 19993157 - 2¹² = 19989061 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 (19992157) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9996578 + 9996579.

It is an arithmetic number, because the mean of its divisors is an integer number (9996579).

Almost surely, 2^19993157 is an apocalyptic number.

It is an amenable number.

19993157 is a deficient number, since it is larger than the sum of its proper divisors (1).

19993157 is an equidigital number, since it uses as much as digits as its factorization.

19993157 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 76545, while the sum is 44.

The square root of 19993157 is about 4471.3708188876. The cubic root of 19993157 is about 271.4108001951.

The spelling of 19993157 in words is "nineteen million, nine hundred ninety-three thousand, one hundred fifty-seven".