261535478989 has 8 divisors (see below), whose sum is σ = 261940861728. Its totient is φ = 261130401840.

The previous prime is 261535478969. The next prime is 261535478993. The reversal of 261535478989 is 989874535162.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-261535478989 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 (261535478969) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1667274 + ... + 1817380.

It is an arithmetic number, because the mean of its divisors is an integer number (32742607716).

Almost surely, 2^261535478989 is an apocalyptic number.

It is an amenable number.

261535478989 is a deficient number, since it is larger than the sum of its proper divisors (405382739).

261535478989 is a wasteful number, since it uses less digits than its factorization.

261535478989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 152795.

The product of its digits is 130636800, while the sum is 67.

The spelling of 261535478989 in words is "two hundred sixty-one billion, five hundred thirty-five million, four hundred seventy-eight thousand, nine hundred eighty-nine".