19145905 has 4 divisors (see below), whose sum is σ = 22975092. Its totient is φ = 15316720.

The previous prime is 19145899. The next prime is 19145923. The reversal of 19145905 is 50954191.

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: 50954191 = 89 ⋅572519.

It can be written as a sum of positive squares in 2 ways, for example, as 11478544 + 7667361 = 3388^2 + 2769^2 .

It is not a de Polignac number, because 19145905 - 2⁹ = 19145393 is a prime.

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, 1914586 + ... + 1914595.

It is an arithmetic number, because the mean of its divisors is an integer number (5743773).

Almost surely, 2^19145905 is an apocalyptic number.

It is an amenable number.

19145905 is a deficient number, since it is larger than the sum of its proper divisors (3829187).

19145905 is an equidigital number, since it uses as much as digits as its factorization.

19145905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3829186.

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

The square root of 19145905 is about 4375.6033869628. The cubic root of 19145905 is about 267.5214644901.

It can be divided in two parts, 19 and 145905, that added together give a square (145924 = 382²).

The spelling of 19145905 in words is "nineteen million, one hundred forty-five thousand, nine hundred five".