1221476928 has 224 divisors, whose sum is σ = 3945233664. Its totient is φ = 325582848.

The previous prime is 1221476923. The next prime is 1221476951. The reversal of 1221476928 is 8296741221.

It is a tau number, because it is divible by the number of its divisors (224).

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a self number, because there is not a number n which added to its sum of digits gives 1221476928.

It is not an unprimeable number, because it can be changed into a prime (1221476923) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4409526 + ... + 4409802.

Almost surely, 2^1221476928 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1221476928, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1972616832).

1221476928 is an abundant number, since it is smaller than the sum of its proper divisors (2723756736).

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

1221476928 is a wasteful number, since it uses less digits than its factorization.

1221476928 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 509 (or 499 counting only the distinct ones).

The product of its digits is 96768, while the sum is 42.

The square root of 1221476928 is about 34949.6341611754. The cubic root of 1221476928 is about 1068.9607424643.

The spelling of 1221476928 in words is "one billion, two hundred twenty-one million, four hundred seventy-six thousand, nine hundred twenty-eight".