661350089 has 4 divisors (see below), whose sum is σ = 663223956. Its totient is φ = 659476224.

The previous prime is 661350083. The next prime is 661350103. The reversal of 661350089 is 980053166.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 980053166 = 2 ⋅490026583.

It can be written as a sum of positive squares in 2 ways, for example, as 172055689 + 489294400 = 13117^2 + 22120^2 .

It is a cyclic number.

It is not a de Polignac number, because 661350089 - 2¹⁶ = 661284553 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (661350083) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 936404 + ... + 937109.

It is an arithmetic number, because the mean of its divisors is an integer number (165805989).

Almost surely, 2^661350089 is an apocalyptic number.

It is an amenable number.

661350089 is a deficient number, since it is larger than the sum of its proper divisors (1873867).

661350089 is a wasteful number, since it uses less digits than its factorization.

661350089 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1873866.

The product of its (nonzero) digits is 38880, while the sum is 38.

The square root of 661350089 is about 25716.7278050688. The cubic root of 661350089 is about 871.2520348896.

The spelling of 661350089 in words is "six hundred sixty-one million, three hundred fifty thousand, eighty-nine".