1223212220 has 48 divisors (see below), whose sum is σ = 2838120768. Its totient is φ = 440478720.

The previous prime is 1223212217. The next prime is 1223212253. The reversal of 1223212220 is 222123221.

It is a Harshad number since it is a multiple of its sum of digits (17).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 70391 + ... + 86030.

It is an arithmetic number, because the mean of its divisors is an integer number (59127516).

Almost surely, 2^1223212220 is an apocalyptic number.

1223212220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1223212220 is an abundant number, since it is smaller than the sum of its proper divisors (1614908548).

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

1223212220 is a wasteful number, since it uses less digits than its factorization.

1223212220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 156470 (or 156468 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 17.

The square root of 1223212220 is about 34974.4509606656. The cubic root of 1223212220 is about 1069.4667095326.

Adding to 1223212220 its reverse (222123221), we get a palindrome (1445335441).

The spelling of 1223212220 in words is "one billion, two hundred twenty-three million, two hundred twelve thousand, two hundred twenty".