1223956440 has 256 divisors, whose sum is σ = 4908672000. Its totient is φ = 265006080.

The previous prime is 1223956423. The next prime is 1223956441. The reversal of 1223956440 is 446593221.

It is a happy number.

1223956440 is a `hidden beast` number, since 1 + 2 + 2 + 3 + 9 + 5 + 644 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 1223956395 and 1223956404.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1223956441) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 139380 + ... + 147900.

It is an arithmetic number, because the mean of its divisors is an integer number (19174500).

Almost surely, 2^1223956440 is an apocalyptic number.

1223956440 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 1223956440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2454336000).

1223956440 is an abundant number, since it is smaller than the sum of its proper divisors (3684715560).

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

1223956440 is a wasteful number, since it uses less digits than its factorization.

1223956440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8567 (or 8557 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 36.

The square root of 1223956440 is about 34985.0888236689. The cubic root of 1223956440 is about 1069.6835585634.

The spelling of 1223956440 in words is "one billion, two hundred twenty-three million, nine hundred fifty-six thousand, four hundred forty".