19966137 has 4 divisors (see below), whose sum is σ = 26621520. Its totient is φ = 13310756.

The previous prime is 19966129. The next prime is 19966183. The reversal of 19966137 is 73166991.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 19966137 - 2³ = 19966129 is a prime.

It is not an unprimeable number, because it can be changed into a prime (19966237) 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 3 ways as a sum of consecutive naturals, for example, 3327687 + ... + 3327692.

It is an arithmetic number, because the mean of its divisors is an integer number (6655380).

Almost surely, 2^19966137 is an apocalyptic number.

It is an amenable number.

19966137 is a deficient number, since it is larger than the sum of its proper divisors (6655383).

19966137 is an equidigital number, since it uses as much as digits as its factorization.

19966137 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6655382.

The product of its digits is 61236, while the sum is 42.

The square root of 19966137 is about 4468.3483525795. The cubic root of 19966137 is about 271.2884779099.

The spelling of 19966137 in words is "nineteen million, nine hundred sixty-six thousand, one hundred thirty-seven".