19917157 has 12 divisors (see below), whose sum is σ = 21901440. Its totient is φ = 18100368.

The previous prime is 19917067. The next prime is 19917167. The reversal of 19917157 is 75171991.

It is a de Polignac number, because none of the positive numbers 2^k-19917157 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19917167) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 10444 + ... + 12202.

It is an arithmetic number, because the mean of its divisors is an integer number (1825120).

Almost surely, 2^19917157 is an apocalyptic number.

It is an amenable number.

19917157 is a deficient number, since it is larger than the sum of its proper divisors (1984283).

19917157 is a wasteful number, since it uses less digits than its factorization.

19917157 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1852 (or 1839 counting only the distinct ones).

The product of its digits is 19845, while the sum is 40.

The square root of 19917157 is about 4462.8642148289. The cubic root of 19917157 is about 271.0664588303.

The spelling of 19917157 in words is "nineteen million, nine hundred seventeen thousand, one hundred fifty-seven".