1565640023 has 8 divisors (see below), whose sum is σ = 1620130080. Its totient is φ = 1511183520.

The previous prime is 1565640001. The next prime is 1565640047. The reversal of 1565640023 is 3200465651.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1565640023 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1565640623) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 120158 + ... + 132548.

It is an arithmetic number, because the mean of its divisors is an integer number (202516260).

Almost surely, 2^1565640023 is an apocalyptic number.

1565640023 is a deficient number, since it is larger than the sum of its proper divisors (54490057).

1565640023 is a wasteful number, since it uses less digits than its factorization.

1565640023 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16777.

The product of its (nonzero) digits is 21600, while the sum is 32.

The square root of 1565640023 is about 39568.1693157518. The cubic root of 1565640023 is about 1161.1740053848.

The spelling of 1565640023 in words is "one billion, five hundred sixty-five million, six hundred forty thousand, twenty-three".