261143999 has 8 divisors (see below), whose sum is σ = 275264880. Its totient is φ = 247060800.

The previous prime is 261143983. The next prime is 261144007. The reversal of 261143999 is 999341162.

It is a happy number.

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

It is not a de Polignac number, because 261143999 - 2⁴ = 261143983 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261143929) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5429 + ... + 23489.

It is an arithmetic number, because the mean of its divisors is an integer number (34408110).

Almost surely, 2^261143999 is an apocalyptic number.

261143999 is a deficient number, since it is larger than the sum of its proper divisors (14120881).

261143999 is a wasteful number, since it uses less digits than its factorization.

261143999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18841.

The product of its digits is 104976, while the sum is 44.

The square root of 261143999 is about 16159.9504640330. The cubic root of 261143999 is about 639.1851600993.

The spelling of 261143999 in words is "two hundred sixty-one million, one hundred forty-three thousand, nine hundred ninety-nine".