1221562944 has 336 divisors, whose sum is σ = 4252976000. Its totient is φ = 347493888.

The previous prime is 1221562933. The next prime is 1221563011. The reversal of 1221562944 is 4492651221.

It is a happy number.

1221562944 is a `hidden beast` number, since 1 + 2 + 2 + 1 + 562 + 94 + 4 = 666.

It is a tau number, because it is divible by the number of its divisors (336).

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 = 1221562899 and 1221562908.

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, 5334222 + ... + 5334450.

Almost surely, 2^1221562944 is an apocalyptic number.

1221562944 is a gapful number since it is divisible by the number (14) 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 1221562944, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2126488000).

1221562944 is an abundant number, since it is smaller than the sum of its proper divisors (3031413056).

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

1221562944 is an frugal number, since it uses more digits than its factorization.

1221562944 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 277 (or 241 counting only the distinct ones).

The product of its digits is 34560, while the sum is 36.

The square root of 1221562944 is about 34950.8647103330. The cubic root of 1221562944 is about 1068.9858338289.

The spelling of 1221562944 in words is "one billion, two hundred twenty-one million, five hundred sixty-two thousand, nine hundred forty-four".