31223400001220 has 192 divisors, whose sum is σ = 76742677863936. Its totient is φ = 10449289543680.

The previous prime is 31223400001133. The next prime is 31223400001231. The reversal of 31223400001220 is 2210000432213.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 31223400001192 and 31223400001201.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1345998662 + ... + 1346021858.

It is an arithmetic number, because the mean of its divisors is an integer number (399701447208).

Almost surely, 2^{31223400001220} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31223400001220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38371338931968).

31223400001220 is an abundant number, since it is smaller than the sum of its proper divisors (45519277862716).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

31223400001220 is a wasteful number, since it uses less digits than its factorization.

31223400001220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24190 (or 24188 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 20.

Adding to 31223400001220 its reverse (2210000432213), we get a palindrome (33433400433433).

The spelling of 31223400001220 in words is "thirty-one trillion, two hundred twenty-three billion, four hundred million, one thousand, two hundred twenty".