31142220 has 24 divisors (see below), whose sum is σ = 87198384. Its totient is φ = 8304576.

The previous prime is 31142219. The next prime is 31142227. The reversal of 31142220 is 2224113.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 31142220.

It is not an unprimeable number, because it can be changed into a prime (31142227) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 259459 + ... + 259578.

It is an arithmetic number, because the mean of its divisors is an integer number (3633266).

Almost surely, 2^31142220 is an apocalyptic number.

31142220 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

31142220 is an abundant number, since it is smaller than the sum of its proper divisors (56056164).

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

31142220 is a wasteful number, since it uses less digits than its factorization.

31142220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 519049 (or 519047 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 15.

The square root of 31142220 is about 5580.5214810087. The cubic root of 31142220 is about 314.6177272552.

Adding to 31142220 its reverse (2224113), we get a palindrome (33366333).

The spelling of 31142220 in words is "thirty-one million, one hundred forty-two thousand, two hundred twenty".