261861769 has 8 divisors (see below), whose sum is σ = 288005760. Its totient is φ = 236575056.

The previous prime is 261861757. The next prime is 261861779. The reversal of 261861769 is 967168162.

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

It is a cyclic number.

It is not a de Polignac number, because 261861769 - 2⁵ = 261861737 is a prime.

It is a super-2 number, since 2×261861769² = 137143172127618722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261861779) 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, 213679 + ... + 214900.

It is an arithmetic number, because the mean of its divisors is an integer number (36000720).

Almost surely, 2^261861769 is an apocalyptic number.

It is an amenable number.

261861769 is a deficient number, since it is larger than the sum of its proper divisors (26143991).

261861769 is a wasteful number, since it uses less digits than its factorization.

261861769 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 428639.

The product of its digits is 217728, while the sum is 46.

The square root of 261861769 is about 16182.1435230318. The cubic root of 261861769 is about 639.7702373483.

The spelling of 261861769 in words is "two hundred sixty-one million, eight hundred sixty-one thousand, seven hundred sixty-nine".