261490739 has 4 divisors (see below), whose sum is σ = 261898056. Its totient is φ = 261083424.

The previous prime is 261490721. The next prime is 261490781. The reversal of 261490739 is 937094162.

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 261490739 - 2²⁰ = 260442163 is a prime.

It is a super-3 number, since 3×261490739³ (a number of 26 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 261490696 and 261490705.

It is not an unprimeable number, because it can be changed into a prime (261499739) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 202694 + ... + 203979.

It is an arithmetic number, because the mean of its divisors is an integer number (65474514).

Almost surely, 2^261490739 is an apocalyptic number.

261490739 is a deficient number, since it is larger than the sum of its proper divisors (407317).

261490739 is an equidigital number, since it uses as much as digits as its factorization.

261490739 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 407316.

The product of its (nonzero) digits is 81648, while the sum is 41.

The square root of 261490739 is about 16170.6752796536. The cubic root of 261490739 is about 639.4679326228.

The spelling of 261490739 in words is "two hundred sixty-one million, four hundred ninety thousand, seven hundred thirty-nine".