21221232011 has 4 divisors (see below), whose sum is σ = 24252836592. Its totient is φ = 18189627432.

The previous prime is 21221231963. The next prime is 21221232023. The reversal of 21221232011 is 11023212212.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21221232011 - 2¹⁸ = 21220969867 is a prime.

It is a super-2 number, since 2×21221232011² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21221232811) 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 3 ways as a sum of consecutive naturals, for example, 1515802280 + ... + 1515802293.

It is an arithmetic number, because the mean of its divisors is an integer number (6063209148).

Almost surely, 2^21221232011 is an apocalyptic number.

21221232011 is a deficient number, since it is larger than the sum of its proper divisors (3031604581).

21221232011 is an equidigital number, since it uses as much as digits as its factorization.

21221232011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3031604580.

The product of its (nonzero) digits is 96, while the sum is 17.

Adding to 21221232011 its reverse (11023212212), we get a palindrome (32244444223).

The spelling of 21221232011 in words is "twenty-one billion, two hundred twenty-one million, two hundred thirty-two thousand, eleven".