21621211401326 has 4 divisors (see below), whose sum is σ = 32431817101992. Its totient is φ = 10810605700662.

The previous prime is 21621211401301. The next prime is 21621211401403. The reversal of 21621211401326 is 62310411212612.

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

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21621211401292 and 21621211401301.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5405302850330 + ... + 5405302850333.

It is an arithmetic number, because the mean of its divisors is an integer number (8107954275498).

Almost surely, 2^{21621211401326} is an apocalyptic number.

21621211401326 is a deficient number, since it is larger than the sum of its proper divisors (10810605700666).

21621211401326 is a wasteful number, since it uses less digits than its factorization.

21621211401326 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10810605700665.

The product of its (nonzero) digits is 6912, while the sum is 32.

Adding to 21621211401326 its reverse (62310411212612), we get a palindrome (83931622613938).

The spelling of 21621211401326 in words is "twenty-one trillion, six hundred twenty-one billion, two hundred eleven million, four hundred one thousand, three hundred twenty-six".