31221200000 has 192 divisors, whose sum is σ = 78706290600. Its totient is φ = 12334080000.

The previous prime is 31221199859. The next prime is 31221200039. The reversal of 31221200000 is 212213.

It is a happy number.

It can be written as a sum of positive squares in 12 ways, for example, as 13718968384 + 17502231616 = 117128^2 + 132296^2 .

It is a super-3 number, since 3×31221200000³ (a number of 32 digits) contains 333 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 35599562 + ... + 35600438.

Almost surely, 2^31221200000 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 31221200000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39353145300).

31221200000 is an abundant number, since it is smaller than the sum of its proper divisors (47485090600).

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

31221200000 is an frugal number, since it uses more digits than its factorization.

31221200000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1005 (or 973 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 11.

Adding to 31221200000 its reverse (212213), we get a palindrome (31221412213).

The spelling of 31221200000 in words is "thirty-one billion, two hundred twenty-one million, two hundred thousand".