21011121305 has 8 divisors (see below), whose sum is σ = 25221073344. Its totient is φ = 16803745200.

The previous prime is 21011121301. The next prime is 21011121331. The reversal of 21011121305 is 50312111012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21011121305 - 2² = 21011121301 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21011121301) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 625991 + ... + 658700.

It is an arithmetic number, because the mean of its divisors is an integer number (3152634168).

Almost surely, 2^21011121305 is an apocalyptic number.

It is an amenable number.

21011121305 is a deficient number, since it is larger than the sum of its proper divisors (4209952039).

21011121305 is a wasteful number, since it uses less digits than its factorization.

21011121305 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1287967.

The product of its (nonzero) digits is 60, while the sum is 17.

Adding to 21011121305 its reverse (50312111012), we get a palindrome (71323232317).

The spelling of 21011121305 in words is "twenty-one billion, eleven million, one hundred twenty-one thousand, three hundred five".