21231220223311 has 12 divisors (see below), whose sum is σ = 24706008819768. Its totient is φ = 18191949974352.

The previous prime is 21231220223309. The next prime is 21231220223329. The reversal of 21231220223311 is 11332202213212.

It is not a de Polignac number, because 21231220223311 - 2¹ = 21231220223309 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21231220223371) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 74126901 + ... + 74412766.

It is an arithmetic number, because the mean of its divisors is an integer number (2058834068314).

Almost surely, 2^{21231220223311} is an apocalyptic number.

21231220223311 is a deficient number, since it is larger than the sum of its proper divisors (3474788596457).

21231220223311 is a wasteful number, since it uses less digits than its factorization.

21231220223311 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 148542598 (or 148542591 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 25.

Adding to 21231220223311 its reverse (11332202213212), we get a palindrome (32563422436523).

The spelling of 21231220223311 in words is "twenty-one trillion, two hundred thirty-one billion, two hundred twenty million, two hundred twenty-three thousand, three hundred eleven".