20409408499 has 2 divisors, whose sum is σ = 20409408500. Its totient is φ = 20409408498.

The previous prime is 20409408473. The next prime is 20409408511. The reversal of 20409408499 is 99480490402.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20409408499 - 2³¹ = 18261924851 is a prime.

It is not a weakly prime, because it can be changed into another prime (20409408419) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10204704249 + 10204704250.

It is an arithmetic number, because the mean of its divisors is an integer number (10204704250).

Almost surely, 2^20409408499 is an apocalyptic number.

20409408499 is a deficient number, since it is larger than the sum of its proper divisors (1).

20409408499 is an equidigital number, since it uses as much as digits as its factorization.

20409408499 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 746496, while the sum is 49.

The spelling of 20409408499 in words is "twenty billion, four hundred nine million, four hundred eight thousand, four hundred ninety-nine".