19823945 has 4 divisors (see below), whose sum is σ = 23788740. Its totient is φ = 15859152.

The previous prime is 19823933. The next prime is 19823957. The reversal of 19823945 is 54932891.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 54932891 = 13 ⋅4225607.

It is an interprime number because it is at equal distance from previous prime (19823933) and next prime (19823957).

It can be written as a sum of positive squares in 2 ways, for example, as 6661561 + 13162384 = 2581^2 + 3628^2 .

It is a cyclic number.

It is not a de Polignac number, because 19823945 - 2¹⁴ = 19807561 is a prime.

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, 1982390 + ... + 1982399.

It is an arithmetic number, because the mean of its divisors is an integer number (5947185).

Almost surely, 2^19823945 is an apocalyptic number.

It is an amenable number.

19823945 is a deficient number, since it is larger than the sum of its proper divisors (3964795).

19823945 is an equidigital number, since it uses as much as digits as its factorization.

19823945 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3964794.

The product of its digits is 77760, while the sum is 41.

The square root of 19823945 is about 4452.4088985627. The cubic root of 19823945 is about 270.6429351081.

The spelling of 19823945 in words is "nineteen million, eight hundred twenty-three thousand, nine hundred forty-five".