1115721457 has 2 divisors, whose sum is σ = 1115721458. Its totient is φ = 1115721456.

The previous prime is 1115721419. The next prime is 1115721463. The reversal of 1115721457 is 7541275111.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 941507856 + 174213601 = 30684^2 + 13199^2 .

It is an emirp because it is prime and its reverse (7541275111) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1115721457 - 2¹⁹ = 1115197169 is a prime.

It is a super-2 number, since 2×1115721457² = 2489668739220405698, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1115721487) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 557860728 + 557860729.

It is an arithmetic number, because the mean of its divisors is an integer number (557860729).

Almost surely, 2^1115721457 is an apocalyptic number.

It is an amenable number.

1115721457 is a deficient number, since it is larger than the sum of its proper divisors (1).

1115721457 is an equidigital number, since it uses as much as digits as its factorization.

1115721457 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9800, while the sum is 34.

The square root of 1115721457 is about 33402.4169335095. The cubic root of 1115721457 is about 1037.1747335133.

Adding to 1115721457 its reverse (7541275111), we get a palindrome (8656996568).

The spelling of 1115721457 in words is "one billion, one hundred fifteen million, seven hundred twenty-one thousand, four hundred fifty-seven".