19966157 has 8 divisors (see below), whose sum is σ = 20317440. Its totient is φ = 19617120.

The previous prime is 19966129. The next prime is 19966183. The reversal of 19966157 is 75166991.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 19966157 - 2¹⁰ = 19965133 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 (19966657) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 34682 + ... + 35252.

It is an arithmetic number, because the mean of its divisors is an integer number (2539680).

Almost surely, 2^19966157 is an apocalyptic number.

It is an amenable number.

19966157 is a deficient number, since it is larger than the sum of its proper divisors (351283).

19966157 is an equidigital number, since it uses as much as digits as its factorization.

19966157 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1123.

The product of its digits is 102060, while the sum is 44.

The square root of 19966157 is about 4468.3505905423. The cubic root of 19966157 is about 271.2885684927.

The spelling of 19966157 in words is "nineteen million, nine hundred sixty-six thousand, one hundred fifty-seven".