21351442211 has 16 divisors (see below), whose sum is σ = 23365480320. Its totient is φ = 19349662080.

The previous prime is 21351442201. The next prime is 21351442237. The reversal of 21351442211 is 11224415312.

It is a happy number.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21351442211 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21351442201) 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, 9127280 + ... + 9129618.

It is an arithmetic number, because the mean of its divisors is an integer number (1460342520).

Almost surely, 2^21351442211 is an apocalyptic number.

21351442211 is a deficient number, since it is larger than the sum of its proper divisors (2014038109).

21351442211 is a wasteful number, since it uses less digits than its factorization.

21351442211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4594.

The product of its digits is 1920, while the sum is 26.

Adding to 21351442211 its reverse (11224415312), we get a palindrome (32575857523).

The spelling of 21351442211 in words is "twenty-one billion, three hundred fifty-one million, four hundred forty-two thousand, two hundred eleven".