261878741 has 2 divisors, whose sum is σ = 261878742. Its totient is φ = 261878740.

The previous prime is 261878737. The next prime is 261878779. The reversal of 261878741 is 147878162.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 170198116 + 91680625 = 13046^2 + 9575^2 .

It is a cyclic number.

It is not a de Polignac number, because 261878741 - 2² = 261878737 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 261878692 and 261878701.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (261878791) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130939370 + 130939371.

It is an arithmetic number, because the mean of its divisors is an integer number (130939371).

Almost surely, 2^261878741 is an apocalyptic number.

It is an amenable number.

261878741 is a deficient number, since it is larger than the sum of its proper divisors (1).

261878741 is an equidigital number, since it uses as much as digits as its factorization.

261878741 is an evil number, because the sum of its binary digits is even.

The product of its digits is 150528, while the sum is 44.

The square root of 261878741 is about 16182.6679197220. The cubic root of 261878741 is about 639.7840588211.

The spelling of 261878741 in words is "two hundred sixty-one million, eight hundred seventy-eight thousand, seven hundred forty-one".