21202120312011 has 24 divisors (see below), whose sum is σ = 32046448065840. Its totient is φ = 13493241268416.

The previous prime is 21202120312001. The next prime is 21202120312013. The reversal of 21202120312011 is 11021302120212.

21202120312011 is a `hidden beast` number, since 21 + 202 + 120 + 312 + 0 + 11 = 666.

It is a de Polignac number, because none of the positive numbers 2^k-21202120312011 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21202120312013) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 600643021 + ... + 600678318.

It is an arithmetic number, because the mean of its divisors is an integer number (1335268669410).

Almost surely, 2^{21202120312011} is an apocalyptic number.

21202120312011 is a deficient number, since it is larger than the sum of its proper divisors (10844327753829).

21202120312011 is a wasteful number, since it uses less digits than its factorization.

21202120312011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1201321435 (or 1201321432 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 18.

Adding to 21202120312011 its reverse (11021302120212), we get a palindrome (32223422432223).

The spelling of 21202120312011 in words is "twenty-one trillion, two hundred two billion, one hundred twenty million, three hundred twelve thousand, eleven".