21121420305 has 8 divisors (see below), whose sum is σ = 33794272512. Its totient is φ = 11264757488.

The previous prime is 21121420291. The next prime is 21121420343. The reversal of 21121420305 is 50302412112.

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

It is a cyclic number.

It is not a de Polignac number, because 21121420305 - 2⁸ = 21121420049 is a prime.

It is a super-2 number, since 2×21121420305² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 704047329 + ... + 704047358.

It is an arithmetic number, because the mean of its divisors is an integer number (4224284064).

Almost surely, 2^21121420305 is an apocalyptic number.

It is an amenable number.

21121420305 is a deficient number, since it is larger than the sum of its proper divisors (12672852207).

21121420305 is a wasteful number, since it uses less digits than its factorization.

21121420305 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1408094695.

The product of its (nonzero) digits is 480, while the sum is 21.

Adding to 21121420305 its reverse (50302412112), we get a palindrome (71423832417).

The spelling of 21121420305 in words is "twenty-one billion, one hundred twenty-one million, four hundred twenty thousand, three hundred five".