261960639 has 8 divisors (see below), whose sum is σ = 364467072. Its totient is φ = 167047320.

The previous prime is 261960617. The next prime is 261960641. The reversal of 261960639 is 936069162.

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

It is not a de Polignac number, because 261960639 - 2⁸ = 261960383 is a prime.

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a self number, because there is not a number n which added to its sum of digits gives 261960639.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261960659) 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, 1898197 + ... + 1898334.

It is an arithmetic number, because the mean of its divisors is an integer number (45558384).

Almost surely, 2^261960639 is an apocalyptic number.

261960639 is a deficient number, since it is larger than the sum of its proper divisors (102506433).

261960639 is a wasteful number, since it uses less digits than its factorization.

261960639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3796557.

The product of its (nonzero) digits is 104976, while the sum is 42.

The square root of 261960639 is about 16185.1981452190. The cubic root of 261960639 is about 639.8507456313.

The spelling of 261960639 in words is "two hundred sixty-one million, nine hundred sixty thousand, six hundred thirty-nine".