31221421224 has 128 divisors (see below), whose sum is σ = 94240665600. Its totient is φ = 8420163840.

The previous prime is 31221421211. The next prime is 31221421237. The reversal of 31221421224 is 42212412213.

It is an interprime number because it is at equal distance from previous prime (31221421211) and next prime (31221421237).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 31221421194 and 31221421203.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 866529 + ... + 901839.

It is an arithmetic number, because the mean of its divisors is an integer number (736255200).

Almost surely, 2^31221421224 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 31221421224, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (47120332800).

31221421224 is an abundant number, since it is smaller than the sum of its proper divisors (63019244376).

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

31221421224 is a wasteful number, since it uses less digits than its factorization.

31221421224 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35623 (or 35619 counting only the distinct ones).

The product of its digits is 1536, while the sum is 24.

Adding to 31221421224 its reverse (42212412213), we get a palindrome (73433833437).

The spelling of 31221421224 in words is "thirty-one billion, two hundred twenty-one million, four hundred twenty-one thousand, two hundred twenty-four".