33231220 has 24 divisors (see below), whose sum is σ = 76130208. Its totient is φ = 12084000.

The previous prime is 33231179. The next prime is 33231221. The reversal of 33231220 is 2213233.

It is a super-4 number, since 4×33231220⁴ (a number of 31 digits) contains 4444 as substring. Note that it is a super-d number also for d = 2.

It is a junction number, because it is equal to n+sod(n) for n = 33231194 and 33231203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (33231221) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 75306 + ... + 75745.

It is an arithmetic number, because the mean of its divisors is an integer number (3172092).

Almost surely, 2^33231220 is an apocalyptic number.

It is an amenable number.

33231220 is an abundant number, since it is smaller than the sum of its proper divisors (42898988).

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

33231220 is a wasteful number, since it uses less digits than its factorization.

33231220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 151071 (or 151069 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 16.

The square root of 33231220 is about 5764.6526348081. The cubic root of 33231220 is about 321.5008275889.

Adding to 33231220 its reverse (2213233), we get a palindrome (35444453).

The spelling of 33231220 in words is "thirty-three million, two hundred thirty-one thousand, two hundred twenty".