19906045 has 4 divisors (see below), whose sum is σ = 23887260. Its totient is φ = 15924832.

The previous prime is 19906043. The next prime is 19906067. The reversal of 19906045 is 54060991.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 54060991 = 1063 ⋅50857.

It can be written as a sum of positive squares in 2 ways, for example, as 8797156 + 11108889 = 2966^2 + 3333^2 .

It is a cyclic number.

It is not a de Polignac number, because 19906045 - 2¹ = 19906043 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 19906045.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19906043) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1990600 + ... + 1990609.

It is an arithmetic number, because the mean of its divisors is an integer number (5971815).

Almost surely, 2^19906045 is an apocalyptic number.

It is an amenable number.

19906045 is a deficient number, since it is larger than the sum of its proper divisors (3981215).

19906045 is an equidigital number, since it uses as much as digits as its factorization.

19906045 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3981214.

The product of its (nonzero) digits is 9720, while the sum is 34.

The square root of 19906045 is about 4461.6191007301. The cubic root of 19906045 is about 271.0160391373.

The spelling of 19906045 in words is "nineteen million, nine hundred six thousand, forty-five".