1228728979 has 4 divisors (see below), whose sum is σ = 1228799880. Its totient is φ = 1228658080.

The previous prime is 1228728961. The next prime is 1228728983. The reversal of 1228728979 is 9798278221.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 1228728979 - 2²⁷ = 1094511251 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1228720979) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9792 + ... + 50530.

It is an arithmetic number, because the mean of its divisors is an integer number (307199970).

Almost surely, 2^1228728979 is an apocalyptic number.

1228728979 is a deficient number, since it is larger than the sum of its proper divisors (70901).

1228728979 is an equidigital number, since it uses as much as digits as its factorization.

1228728979 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 70900.

The product of its digits is 2032128, while the sum is 55.

The square root of 1228728979 is about 35053.2306499701. The cubic root of 1228728979 is about 1071.0720844051.

The spelling of 1228728979 in words is "one billion, two hundred twenty-eight million, seven hundred twenty-eight thousand, nine hundred seventy-nine".