20842293509 has 2 divisors, whose sum is σ = 20842293510. Its totient is φ = 20842293508.

The previous prime is 20842293499. The next prime is 20842293559. The reversal of 20842293509 is 90539224802.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19761330625 + 1080962884 = 140575^2 + 32878^2 .

It is a cyclic number.

It is not a de Polignac number, because 20842293509 - 2²⁴ = 20825516293 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 20842293509.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20842293559) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10421146754 + 10421146755.

It is an arithmetic number, because the mean of its divisors is an integer number (10421146755).

Almost surely, 2^20842293509 is an apocalyptic number.

It is an amenable number.

20842293509 is a deficient number, since it is larger than the sum of its proper divisors (1).

20842293509 is an equidigital number, since it uses as much as digits as its factorization.

20842293509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 311040, while the sum is 44.

The spelling of 20842293509 in words is "twenty billion, eight hundred forty-two million, two hundred ninety-three thousand, five hundred nine".