21203405415011 has 4 divisors (see below), whose sum is σ = 22125292606992. Its totient is φ = 20281518223032.

The previous prime is 21203405414981. The next prime is 21203405415047. The reversal of 21203405415011 is 11051450430212.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21203405415011 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21203405417011) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 460943595956 + ... + 460943596001.

It is an arithmetic number, because the mean of its divisors is an integer number (5531323151748).

Almost surely, 2^{21203405415011} is an apocalyptic number.

21203405415011 is a deficient number, since it is larger than the sum of its proper divisors (921887191981).

21203405415011 is an equidigital number, since it uses as much as digits as its factorization.

21203405415011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 921887191980.

The product of its (nonzero) digits is 4800, while the sum is 29.

Adding to 21203405415011 its reverse (11051450430212), we get a palindrome (32254855845223).

The spelling of 21203405415011 in words is "twenty-one trillion, two hundred three billion, four hundred five million, four hundred fifteen thousand, eleven".