261043366 has 4 divisors (see below), whose sum is σ = 391565052. Its totient is φ = 130521682.

The previous prime is 261043361. The next prime is 261043379. The reversal of 261043366 is 663340162.

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

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261043361) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 65260840 + ... + 65260843.

It is an arithmetic number, because the mean of its divisors is an integer number (97891263).

Almost surely, 2^261043366 is an apocalyptic number.

261043366 is a deficient number, since it is larger than the sum of its proper divisors (130521686).

261043366 is a wasteful number, since it uses less digits than its factorization.

261043366 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 130521685.

The product of its (nonzero) digits is 15552, while the sum is 31.

The square root of 261043366 is about 16156.8365096636. The cubic root of 261043366 is about 639.1030452704.

The spelling of 261043366 in words is "two hundred sixty-one million, forty-three thousand, three hundred sixty-six".