261477261 has 16 divisors (see below), whose sum is σ = 397844800. Its totient is φ = 169606224.

The previous prime is 261477257. The next prime is 261477287. The reversal of 261477261 is 162774162.

It is not a de Polignac number, because 261477261 - 2² = 261477257 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 (261477211) 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 15 ways as a sum of consecutive naturals, for example, 129871 + ... + 131868.

It is an arithmetic number, because the mean of its divisors is an integer number (24865300).

Almost surely, 2^261477261 is an apocalyptic number.

It is an amenable number.

261477261 is a deficient number, since it is larger than the sum of its proper divisors (136367539).

261477261 is a wasteful number, since it uses less digits than its factorization.

261477261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 261785 (or 261779 counting only the distinct ones).

The product of its digits is 28224, while the sum is 36.

The square root of 261477261 is about 16170.2585322561. The cubic root of 261477261 is about 639.4569457495.

The spelling of 261477261 in words is "two hundred sixty-one million, four hundred seventy-seven thousand, two hundred sixty-one".