1228640885 has 4 divisors (see below), whose sum is σ = 1474369068. Its totient is φ = 982912704.

The previous prime is 1228640879. The next prime is 1228640893. The reversal of 1228640885 is 5880468221.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 693690244 + 534950641 = 26338^2 + 23129^2 .

It is a cyclic number.

It is not a de Polignac number, because 1228640885 - 2⁸ = 1228640629 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 122864084 + ... + 122864093.

It is an arithmetic number, because the mean of its divisors is an integer number (368592267).

Almost surely, 2^1228640885 is an apocalyptic number.

It is an amenable number.

1228640885 is a deficient number, since it is larger than the sum of its proper divisors (245728183).

1228640885 is an equidigital number, since it uses as much as digits as its factorization.

1228640885 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 245728182.

The product of its (nonzero) digits is 245760, while the sum is 44.

The square root of 1228640885 is about 35051.9740528262. The cubic root of 1228640885 is about 1071.0464868755.

The spelling of 1228640885 in words is "one billion, two hundred twenty-eight million, six hundred forty thousand, eight hundred eighty-five".