1355097661 has 4 divisors (see below), whose sum is σ = 1355648092. Its totient is φ = 1354547232.

The previous prime is 1355097629. The next prime is 1355097671. The reversal of 1355097661 is 1667905531.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1667905531 = 223 ⋅7479397.

It can be written as a sum of positive squares in 2 ways, for example, as 989102500 + 365995161 = 31450^2 + 19131^2 .

It is a cyclic number.

It is not a de Polignac number, because 1355097661 - 2⁵ = 1355097629 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1355097671) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 271506 + ... + 276451.

It is an arithmetic number, because the mean of its divisors is an integer number (338912023).

Almost surely, 2^1355097661 is an apocalyptic number.

It is an amenable number.

1355097661 is a deficient number, since it is larger than the sum of its proper divisors (550431).

1355097661 is an equidigital number, since it uses as much as digits as its factorization.

1355097661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 550430.

The product of its (nonzero) digits is 170100, while the sum is 43.

The square root of 1355097661 is about 36811.6511582950. The cubic root of 1355097661 is about 1106.5988092354.

The spelling of 1355097661 in words is "one billion, three hundred fifty-five million, ninety-seven thousand, six hundred sixty-one".