20565740819 has 16 divisors (see below), whose sum is σ = 22265913600. Its totient is φ = 18882602496.

The previous prime is 20565740813. The next prime is 20565740827. The reversal of 20565740819 is 91804756502.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 20565740819 - 2⁸ = 20565740563 is a prime.

It is a super-2 number, since 2×20565740819² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20565740813) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4662287 + ... + 4666695.

It is an arithmetic number, because the mean of its divisors is an integer number (1391619600).

Almost surely, 2^20565740819 is an apocalyptic number.

20565740819 is a deficient number, since it is larger than the sum of its proper divisors (1700172781).

20565740819 is a wasteful number, since it uses less digits than its factorization.

20565740819 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6254.

The product of its (nonzero) digits is 604800, while the sum is 47.

The spelling of 20565740819 in words is "twenty billion, five hundred sixty-five million, seven hundred forty thousand, eight hundred nineteen".