21305631011 has 16 divisors (see below), whose sum is σ = 24453831936. Its totient is φ = 18183717216.

The previous prime is 21305630993. The next prime is 21305631047. The reversal of 21305631011 is 11013650312.

It is not a de Polignac number, because 21305631011 - 2¹⁸ = 21305368867 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21305631071) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1832960 + ... + 1844546.

It is an arithmetic number, because the mean of its divisors is an integer number (1528364496).

Almost surely, 2^21305631011 is an apocalyptic number.

21305631011 is a deficient number, since it is larger than the sum of its proper divisors (3148200925).

21305631011 is a wasteful number, since it uses less digits than its factorization.

21305631011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12698.

The product of its (nonzero) digits is 540, while the sum is 23.

The spelling of 21305631011 in words is "twenty-one billion, three hundred five million, six hundred thirty-one thousand, eleven".