1223651220 has 144 divisors (see below), whose sum is σ = 3888213504. Its totient is φ = 287020800.

The previous prime is 1223651207. The next prime is 1223651263. The reversal of 1223651220 is 221563221.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 222342 + ... + 227778.

Almost surely, 2^1223651220 is an apocalyptic number.

1223651220 is a gapful number since it is divisible by the number (10) 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 1223651220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1944106752).

1223651220 is an abundant number, since it is smaller than the sum of its proper divisors (2664562284).

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

1223651220 is a wasteful number, since it uses less digits than its factorization.

1223651220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5502 (or 5489 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 24.

The square root of 1223651220 is about 34980.7264075519. The cubic root of 1223651220 is about 1069.5946349308.

The spelling of 1223651220 in words is "one billion, two hundred twenty-three million, six hundred fifty-one thousand, two hundred twenty".