19666042 has 16 divisors (see below), whose sum is σ = 34074432. Its totient is φ = 8413120.

The previous prime is 19666039. The next prime is 19666043. The reversal of 19666042 is 24066691.

It is a Harshad number since it is a multiple of its sum of digits (34).

It is a junction number, because it is equal to n+sod(n) for n = 19665989 and 19666007.

It is not an unprimeable number, because it can be changed into a prime (19666043) 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, 25918 + ... + 26665.

It is an arithmetic number, because the mean of its divisors is an integer number (2129652).

Almost surely, 2^19666042 is an apocalyptic number.

19666042 is a deficient number, since it is larger than the sum of its proper divisors (14408390).

19666042 is a wasteful number, since it uses less digits than its factorization.

19666042 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52613.

The product of its (nonzero) digits is 15552, while the sum is 34.

The square root of 19666042 is about 4434.6411354246. The cubic root of 19666042 is about 269.9224377118.

It can be divided in two parts, 1966 and 6042, that added together give a palindrome (8008).

The spelling of 19666042 in words is "nineteen million, six hundred sixty-six thousand, forty-two".