15780243 has 4 divisors (see below), whose sum is σ = 21040328. Its totient is φ = 10520160.

The previous prime is 15780239. The next prime is 15780283. The reversal of 15780243 is 34208751.

15780243 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 15780243 - 2² = 15780239 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 15780243.

It is not an unprimeable number, because it can be changed into a prime (15780283) 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, 2630038 + ... + 2630043.

It is an arithmetic number, because the mean of its divisors is an integer number (5260082).

Almost surely, 2^15780243 is an apocalyptic number.

15780243 is a deficient number, since it is larger than the sum of its proper divisors (5260085).

15780243 is an equidigital number, since it uses as much as digits as its factorization.

15780243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5260084.

The product of its (nonzero) digits is 6720, while the sum is 30.

The square root of 15780243 is about 3972.4353990971. The cubic root of 15780243 is about 250.8252356141.

Adding to 15780243 its reverse (34208751), we get a palindrome (49988994).

The spelling of 15780243 in words is "fifteen million, seven hundred eighty thousand, two hundred forty-three".