1100728561 has 2 divisors, whose sum is σ = 1100728562. Its totient is φ = 1100728560.

The previous prime is 1100728537. The next prime is 1100728571. The reversal of 1100728561 is 1658270011.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1086097936 + 14630625 = 32956^2 + 3825^2 .

It is a cyclic number.

It is not a de Polignac number, because 1100728561 - 2⁹ = 1100728049 is a prime.

It is a super-2 number, since 2×1100728561² = 2423206730002261442, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1100728511) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 550364280 + 550364281.

It is an arithmetic number, because the mean of its divisors is an integer number (550364281).

Almost surely, 2^1100728561 is an apocalyptic number.

It is an amenable number.

1100728561 is a deficient number, since it is larger than the sum of its proper divisors (1).

1100728561 is an equidigital number, since it uses as much as digits as its factorization.

1100728561 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3360, while the sum is 31.

The square root of 1100728561 is about 33177.2295558264. The cubic root of 1100728561 is about 1032.5079678967.

Adding to 1100728561 its reverse (1658270011), we get a palindrome (2758998572).

The spelling of 1100728561 in words is "one billion, one hundred million, seven hundred twenty-eight thousand, five hundred sixty-one".