1227638745 has 12 divisors (see below), whose sum is σ = 2127907236. Its totient is φ = 654740640.

The previous prime is 1227638729. The next prime is 1227638747. The reversal of 1227638745 is 5478367221.

1227638745 is a `hidden beast` number, since 1 + 2 + 2 + 7 + 638 + 7 + 4 + 5 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 324756441 + 902882304 = 18021^2 + 30048^2 .

It is not a de Polignac number, because 1227638745 - 2⁴ = 1227638729 is a prime.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (45), and also a Moran number because the ratio is a prime number: 27280861 = 1227638745 / (1 + 2 + 2 + 7 + 6 + 3 + 8 + 7 + 4 + 5).

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 1227638745.

It is not an unprimeable number, because it can be changed into a prime (1227638747) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 13640386 + ... + 13640475.

It is an arithmetic number, because the mean of its divisors is an integer number (177325603).

Almost surely, 2^1227638745 is an apocalyptic number.

1227638745 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1227638745 is a deficient number, since it is larger than the sum of its proper divisors (900268491).

1227638745 is a wasteful number, since it uses less digits than its factorization.

1227638745 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27280872 (or 27280869 counting only the distinct ones).

The product of its digits is 564480, while the sum is 45.

The square root of 1227638745 is about 35037.6760787584. The cubic root of 1227638745 is about 1070.7552082509.

The spelling of 1227638745 in words is "one billion, two hundred twenty-seven million, six hundred thirty-eight thousand, seven hundred forty-five".