961215889 has 4 divisors (see below), whose sum is σ = 970732980. Its totient is φ = 951698800.

The previous prime is 961215881. The next prime is 961215901. The reversal of 961215889 is 988512169.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 988512169 = 53 ⋅18651173.

It can be written as a sum of positive squares in 2 ways, for example, as 943718400 + 17497489 = 30720^2 + 4183^2 .

It is a cyclic number.

It is not a de Polignac number, because 961215889 - 2³ = 961215881 is a prime.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (961215881) 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, 4758394 + ... + 4758595.

It is an arithmetic number, because the mean of its divisors is an integer number (242683245).

Almost surely, 2^961215889 is an apocalyptic number.

It is an amenable number.

961215889 is a deficient number, since it is larger than the sum of its proper divisors (9517091).

961215889 is a wasteful number, since it uses less digits than its factorization.

961215889 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9517090.

The product of its digits is 311040, while the sum is 49.

The square root of 961215889 is about 31003.4818851045. The cubic root of 961215889 is about 986.9011318219.

The spelling of 961215889 in words is "nine hundred sixty-one million, two hundred fifteen thousand, eight hundred eighty-nine".