261728935651 has 4 divisors (see below), whose sum is σ = 261730426072. Its totient is φ = 261727445232.

The previous prime is 261728935609. The next prime is 261728935667. The reversal of 261728935651 is 156539827162.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 261728935651 - 2¹¹ = 261728933603 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 261728935592 and 261728935601.

It is not an unprimeable number, because it can be changed into a prime (261728935691) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 440181 + ... + 846886.

It is an arithmetic number, because the mean of its divisors is an integer number (65432606518).

Almost surely, 2^261728935651 is an apocalyptic number.

261728935651 is a deficient number, since it is larger than the sum of its proper divisors (1490421).

261728935651 is a wasteful number, since it uses less digits than its factorization.

261728935651 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1490420.

The product of its digits is 5443200, while the sum is 55.

The spelling of 261728935651 in words is "two hundred sixty-one billion, seven hundred twenty-eight million, nine hundred thirty-five thousand, six hundred fifty-one".