31220400000 has 192 divisors, whose sum is σ = 103658834160. Its totient is φ = 8325120000.

The previous prime is 31220399999. The next prime is 31220400019. The reversal of 31220400000 is 402213.

It is a tau number, because it is divible by the number of its divisors (192).

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a congruent number.

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 1186992 + ... + 1213008.

Almost surely, 2^31220400000 is an apocalyptic number.

31220400000 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31220400000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (51829417080).

31220400000 is an abundant number, since it is smaller than the sum of its proper divisors (72438434160).

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

31220400000 is an frugal number, since it uses more digits than its factorization.

31220400000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26059 (or 26027 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 12.

Adding to 31220400000 its reverse (402213), we get a palindrome (31220802213).

The spelling of 31220400000 in words is "thirty-one billion, two hundred twenty million, four hundred thousand".