261064636245 has 96 divisors (see below), whose sum is σ = 521928126720. Its totient is φ = 118247592960.

The previous prime is 261064636199. The next prime is 261064636267. The reversal of 261064636245 is 542636460162.

It is a happy number.

261064636245 is a `hidden beast` number, since 2 + 6 + 1 + 0 + 6 + 4 + 636 + 2 + 4 + 5 = 666.

It is not a de Polignac number, because 261064636245 - 2⁶ = 261064636181 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 261064636245.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 15835947 + ... + 15852423.

It is an arithmetic number, because the mean of its divisors is an integer number (5436751320).

Almost surely, 2^261064636245 is an apocalyptic number.

It is an amenable number.

261064636245 is a deficient number, since it is larger than the sum of its proper divisors (260863490475).

261064636245 is a wasteful number, since it uses less digits than its factorization.

261064636245 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16955 (or 16952 counting only the distinct ones).

The product of its (nonzero) digits is 1244160, while the sum is 45.

The spelling of 261064636245 in words is "two hundred sixty-one billion, sixty-four million, six hundred thirty-six thousand, two hundred forty-five".