19945105 has 4 divisors (see below), whose sum is σ = 23934132. Its totient is φ = 15956080.

The previous prime is 19945091. The next prime is 19945111. The reversal of 19945105 is 50154991.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 50154991 = 83 ⋅604277.

It can be written as a sum of positive squares in 2 ways, for example, as 3873024 + 16072081 = 1968^2 + 4009^2 .

It is not a de Polignac number, because 19945105 - 2⁹ = 19944593 is a prime.

It is a super-2 number, since 2×19945105² = 795614426922050, which contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1994506 + ... + 1994515.

It is an arithmetic number, because the mean of its divisors is an integer number (5983533).

Almost surely, 2^19945105 is an apocalyptic number.

It is an amenable number.

19945105 is a deficient number, since it is larger than the sum of its proper divisors (3989027).

19945105 is an equidigital number, since it uses as much as digits as its factorization.

19945105 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3989026.

The product of its (nonzero) digits is 8100, while the sum is 34.

The square root of 19945105 is about 4465.9942901889. The cubic root of 19945105 is about 271.1931875042.

The spelling of 19945105 in words is "nineteen million, nine hundred forty-five thousand, one hundred five".