1564136243 has 4 divisors (see below), whose sum is σ = 1565232240. Its totient is φ = 1563040248.

The previous prime is 1564136237. The next prime is 1564136311. The reversal of 1564136243 is 3426314651.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3426314651 = 173 ⋅19805287.

It is a cyclic number.

It is not a de Polignac number, because 1564136243 - 2¹⁰ = 1564135219 is a prime.

It is a super-3 number, since 3×1564136243³ (a number of 29 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1564133243) 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, 545855 + ... + 548712.

It is an arithmetic number, because the mean of its divisors is an integer number (391308060).

Almost surely, 2^1564136243 is an apocalyptic number.

1564136243 is a deficient number, since it is larger than the sum of its proper divisors (1095997).

1564136243 is a wasteful number, since it uses less digits than its factorization.

1564136243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1095996.

The product of its digits is 51840, while the sum is 35.

The square root of 1564136243 is about 39549.1623552257. The cubic root of 1564136243 is about 1160.8021213477.

The spelling of 1564136243 in words is "one billion, five hundred sixty-four million, one hundred thirty-six thousand, two hundred forty-three".