261684997 has 8 divisors (see below), whose sum is σ = 299414336. Its totient is φ = 224042112.

The previous prime is 261684991. The next prime is 261685003. The reversal of 261684997 is 799486162.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (261684991) and next prime (261685003).

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

It is not a de Polignac number, because 261684997 - 2³ = 261684989 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 (261684991) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14988 + ... + 27349.

It is an arithmetic number, because the mean of its divisors is an integer number (37426792).

Almost surely, 2^261684997 is an apocalyptic number.

It is an amenable number.

261684997 is a deficient number, since it is larger than the sum of its proper divisors (37729339).

261684997 is an equidigital number, since it uses as much as digits as its factorization.

261684997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43227.

The product of its digits is 1306368, while the sum is 52.

The square root of 261684997 is about 16176.6806545719. The cubic root of 261684997 is about 639.6262441739.

The spelling of 261684997 in words is "two hundred sixty-one million, six hundred eighty-four thousand, nine hundred ninety-seven".