31232221020 has 576 divisors, whose sum is σ = 128583576576. Its totient is φ = 5925519360.

The previous prime is 31232220991. The next prime is 31232221039. The reversal of 31232221020 is 2012223213.

31232221020 is a `hidden beast` number, since 312 + 322 + 2 + 10 + 20 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 31232220984 and 31232221002.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 17476567 + ... + 17478353.

It is an arithmetic number, because the mean of its divisors is an integer number (223235376).

Almost surely, 2^31232221020 is an apocalyptic number.

31232221020 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 31232221020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (64291788288).

31232221020 is an abundant number, since it is smaller than the sum of its proper divisors (97351355556).

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

31232221020 is a wasteful number, since it uses less digits than its factorization.

31232221020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1930 (or 1925 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 18.

Adding to 31232221020 its reverse (2012223213), we get a palindrome (33244444233).

It can be divided in two parts, 31232 and 221020, that added together give a palindrome (252252).

The spelling of 31232221020 in words is "thirty-one billion, two hundred thirty-two million, two hundred twenty-one thousand, twenty".