261749801 has 8 divisors (see below), whose sum is σ = 266329440. Its totient is φ = 257206752.

The previous prime is 261749797. The next prime is 261749837. The reversal of 261749801 is 108947162.

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 261749801 - 2² = 261749797 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261749861) 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, 5486 + ... + 23528.

It is an arithmetic number, because the mean of its divisors is an integer number (33291180).

Almost surely, 2^261749801 is an apocalyptic number.

It is an amenable number.

261749801 is a deficient number, since it is larger than the sum of its proper divisors (4579639).

261749801 is a wasteful number, since it uses less digits than its factorization.

261749801 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18295.

The product of its (nonzero) digits is 24192, while the sum is 38.

The square root of 261749801 is about 16178.6835372968. The cubic root of 261749801 is about 639.6790390971.

The spelling of 261749801 in words is "two hundred sixty-one million, seven hundred forty-nine thousand, eight hundred one".