87960289561 has 3 divisors (see below), whose sum is σ = 87960586143. Its totient is φ = 87959992980.

The previous prime is 87960289559. The next prime is 87960289579. The reversal of 87960289561 is 16598206978.

The square root of 87960289561 is 296581.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 50005457161 + 37954832400 = 223619^2 + 194820^2 .

It is not a de Polignac number, because 87960289561 - 2¹ = 87960289559 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 87960289561.

It is not an unprimeable number, because it can be changed into a prime (87960289861) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 148291 + ... + 444871.

It is an arithmetic number, because the mean of its divisors is an integer number (29320195381).

Almost surely, 2^87960289561 is an apocalyptic number.

87960289561 is the 296581-st square number.

87960289561 is the 148291-st centered octagonal number.

It is an amenable number.

87960289561 is a deficient number, since it is larger than the sum of its proper divisors (296582).

87960289561 is an frugal number, since it uses more digits than its factorization.

87960289561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 593162 (or 296581 counting only the distinct ones).

The product of its (nonzero) digits is 13063680, while the sum is 61.

The spelling of 87960289561 in words is "eighty-seven billion, nine hundred sixty million, two hundred eighty-nine thousand, five hundred sixty-one".