20191345 has 4 divisors (see below), whose sum is σ = 24229620. Its totient is φ = 16153072.

The previous prime is 20191343. The next prime is 20191351. The reversal of 20191345 is 54319102.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 54319102 = 2 ⋅27159551.

It can be written as a sum of positive squares in 2 ways, for example, as 12222016 + 7969329 = 3496^2 + 2823^2 .

It is a cyclic number.

It is not a de Polignac number, because 20191345 - 2¹ = 20191343 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20191343) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2019130 + ... + 2019139.

It is an arithmetic number, because the mean of its divisors is an integer number (6057405).

Almost surely, 2^20191345 is an apocalyptic number.

It is an amenable number.

20191345 is a deficient number, since it is larger than the sum of its proper divisors (4038275).

20191345 is an equidigital number, since it uses as much as digits as its factorization.

20191345 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4038274.

The product of its (nonzero) digits is 1080, while the sum is 25.

The square root of 20191345 is about 4493.4780515765. The cubic root of 20191345 is about 272.3046660065.

It can be divided in two parts, 2019 and 1345, that added together give a square (3364 = 58²).

The spelling of 20191345 in words is "twenty million, one hundred ninety-one thousand, three hundred forty-five".