1155781028 has 6 divisors (see below), whose sum is σ = 2022616806. Its totient is φ = 577890512.

The previous prime is 1155781019. The next prime is 1155781037. The reversal of 1155781028 is 8201875511.

It is an interprime number because it is at equal distance from previous prime (1155781019) and next prime (1155781037).

It can be written as a sum of positive squares in only one way, i.e., 1018375744 + 137405284 = 31912^2 + 11722^2 .

It is a junction number, because it is equal to n+sod(n) for n = 1155780982 and 1155781000.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 144472625 + ... + 144472632.

It is an arithmetic number, because the mean of its divisors is an integer number (337102801).

Almost surely, 2^1155781028 is an apocalyptic number.

It is an amenable number.

1155781028 is a deficient number, since it is larger than the sum of its proper divisors (866835778).

1155781028 is a wasteful number, since it uses less digits than its factorization.

1155781028 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 288945261 (or 288945259 counting only the distinct ones).

The product of its (nonzero) digits is 22400, while the sum is 38.

The square root of 1155781028 is about 33996.7796710218. The cubic root of 1155781028 is about 1049.4421913982.

The spelling of 1155781028 in words is "one billion, one hundred fifty-five million, seven hundred eighty-one thousand, twenty-eight".