261788047 has 4 divisors (see below), whose sum is σ = 273170160. Its totient is φ = 250405936.

The previous prime is 261788029. The next prime is 261788063. The reversal of 261788047 is 740887162.

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 261788047 - 2⁷ = 261787919 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 261787994 and 261788012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261788347) 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, 5691022 + ... + 5691067.

It is an arithmetic number, because the mean of its divisors is an integer number (68292540).

Almost surely, 2^261788047 is an apocalyptic number.

261788047 is a deficient number, since it is larger than the sum of its proper divisors (11382113).

261788047 is a wasteful number, since it uses less digits than its factorization.

261788047 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11382112.

The product of its (nonzero) digits is 150528, while the sum is 43.

The square root of 261788047 is about 16179.8654815175. The cubic root of 261788047 is about 639.7101934959.

It can be divided in two parts, 26178 and 8047, that added together give a square (34225 = 185²).

The spelling of 261788047 in words is "two hundred sixty-one million, seven hundred eighty-eight thousand, forty-seven".