1136721661 has 2 divisors, whose sum is σ = 1136721662. Its totient is φ = 1136721660.

The previous prime is 1136721629. The next prime is 1136721689. The reversal of 1136721661 is 1661276311.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 634737636 + 501984025 = 25194^2 + 22405^2 .

It is a cyclic number.

It is not a de Polignac number, because 1136721661 - 2⁵ = 1136721629 is a prime.

It is a super-2 number, since 2×1136721661² = 2584272269173197842, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1136728661) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 568360830 + 568360831.

It is an arithmetic number, because the mean of its divisors is an integer number (568360831).

Almost surely, 2^1136721661 is an apocalyptic number.

It is an amenable number.

1136721661 is a deficient number, since it is larger than the sum of its proper divisors (1).

1136721661 is an equidigital number, since it uses as much as digits as its factorization.

1136721661 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 9072, while the sum is 34.

The square root of 1136721661 is about 33715.3030684881. The cubic root of 1136721661 is about 1043.6415920204.

Adding to 1136721661 its reverse (1661276311), we get a palindrome (2797997972).

The spelling of 1136721661 in words is "one billion, one hundred thirty-six million, seven hundred twenty-one thousand, six hundred sixty-one".