1148778819721 has 27 divisors (see below), whose sum is σ = 1288770985749. Its totient is φ = 1023485185632.

The previous prime is 1148778819719. The next prime is 1148778819731. The reversal of 1148778819721 is 1279188778411.

The square root of 1148778819721 is 1071811.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 147306278025 + 1001472541696 = 383805^2 + 1000736^2 .

It is not a de Polignac number, because 1148778819721 - 2¹ = 1148778819719 is a prime.

It is a Smith number, since the sum of its digits (64) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (1148778819731) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 404071326 + ... + 404074168.

Almost surely, 2^{1148778819721} is an apocalyptic number.

1148778819721 is the 1071811-st square number.

1148778819721 is the 535906-th centered octagonal number.

It is an amenable number.

1148778819721 is a deficient number, since it is larger than the sum of its proper divisors (139992166028).

1148778819721 is an frugal number, since it uses more digits than its factorization.

1148778819721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5770 (or 2885 counting only the distinct ones).

The product of its digits is 12644352, while the sum is 64.

Multiplying 1148778819721 by its sum of digits (64), we get a square (73521844462144 = 8574488²).

The spelling of 1148778819721 in words is "one trillion, one hundred forty-eight billion, seven hundred seventy-eight million, eight hundred nineteen thousand, seven hundred twenty-one".