31220212 has 6 divisors (see below), whose sum is σ = 54635378. Its totient is φ = 15610104.

The previous prime is 31220209. The next prime is 31220213. The reversal of 31220212 is 21202213.

It can be written as a sum of positive squares in only one way, i.e., 25040016 + 6180196 = 5004^2 + 2486^2 .

It is a junction number, because it is equal to n+sod(n) for n = 31220192 and 31220201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31220213) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3902523 + ... + 3902530.

Almost surely, 2^31220212 is an apocalyptic number.

It is an amenable number.

31220212 is a deficient number, since it is larger than the sum of its proper divisors (23415166).

31220212 is a wasteful number, since it uses less digits than its factorization.

31220212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7805057 (or 7805055 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 13.

The square root of 31220212 is about 5587.5049888121. The cubic root of 31220212 is about 314.8801492485.

Adding to 31220212 its reverse (21202213), we get a palindrome (52422425).

The spelling of 31220212 in words is "thirty-one million, two hundred twenty thousand, two hundred twelve".