31222000 has 80 divisors (see below), whose sum is σ = 76950432. Its totient is φ = 12249600.

The previous prime is 31221977. The next prime is 31222021. The reversal of 31222000 is 22213.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (10).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 133884 + ... + 134116.

Almost surely, 2^31222000 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 31222000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38475216).

31222000 is an abundant number, since it is smaller than the sum of its proper divisors (45728432).

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

31222000 is a wasteful number, since it uses less digits than its factorization.

31222000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 323 (or 307 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 10.

The square root of 31222000 is about 5587.6649863785. The cubic root of 31222000 is about 314.8861602579.

Adding to 31222000 its reverse (22213), we get a palindrome (31244213).

The spelling of 31222000 in words is "thirty-one million, two hundred twenty-two thousand".