20768242509 has 32 divisors (see below), whose sum is σ = 35217219840. Its totient is φ = 11849322816.

The previous prime is 20768242499. The next prime is 20768242511. The reversal of 20768242509 is 90524286702.

20768242509 is a `hidden beast` number, since 20 + 7 + 6 + 82 + 42 + 509 = 666.

It is not a de Polignac number, because 20768242509 - 2²⁹ = 20231371597 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20768242519) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 39279 + ... + 207555.

It is an arithmetic number, because the mean of its divisors is an integer number (1100538120).

Almost surely, 2^20768242509 is an apocalyptic number.

It is an amenable number.

20768242509 is a deficient number, since it is larger than the sum of its proper divisors (14448977331).

20768242509 is a wasteful number, since it uses less digits than its factorization.

20768242509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 168946 (or 168940 counting only the distinct ones).

The product of its (nonzero) digits is 483840, while the sum is 45.

The spelling of 20768242509 in words is "twenty billion, seven hundred sixty-eight million, two hundred forty-two thousand, five hundred nine".