31012020 has 144 divisors (see below), whose sum is σ = 105028560. Its totient is φ = 7354368.

The previous prime is 31012013. The next prime is 31012021. The reversal of 31012020 is 2021013.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 76176 + 30935844 = 276^2 + 5562^2 .

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a junction number, because it is equal to n+sod(n) for n = 31011993 and 31012011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31012021) 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 47 ways as a sum of consecutive naturals, for example, 67632 + ... + 68088.

It is an arithmetic number, because the mean of its divisors is an integer number (729365).

Almost surely, 2^31012020 is an apocalyptic number.

31012020 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 31012020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (52514280).

31012020 is an abundant number, since it is smaller than the sum of its proper divisors (74016540).

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

31012020 is a wasteful number, since it uses less digits than its factorization.

31012020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 514 (or 509 counting only the distinct ones).

The product of its (nonzero) digits is 12, while the sum is 9.

The square root of 31012020 is about 5568.8436860806. The cubic root of 31012020 is about 314.1786614931.

Adding to 31012020 its reverse (2021013), we get a palindrome (33033033).

The spelling of 31012020 in words is "thirty-one million, twelve thousand, twenty".