261862901 has 2 divisors, whose sum is σ = 261862902. Its totient is φ = 261862900.

The previous prime is 261862891. The next prime is 261862903. The reversal of 261862901 is 109268162.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 203034001 + 58828900 = 14249^2 + 7670^2 .

It is a cyclic number.

It is not a de Polignac number, because 261862901 - 2¹⁴ = 261846517 is a prime.

Together with 261862903, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (261862903) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130931450 + 130931451.

It is an arithmetic number, because the mean of its divisors is an integer number (130931451).

Almost surely, 2^261862901 is an apocalyptic number.

It is an amenable number.

261862901 is a deficient number, since it is larger than the sum of its proper divisors (1).

261862901 is an equidigital number, since it uses as much as digits as its factorization.

261862901 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10368, while the sum is 35.

The square root of 261862901 is about 16182.1784998189. The cubic root of 261862901 is about 639.7711592328.

The spelling of 261862901 in words is "two hundred sixty-one million, eight hundred sixty-two thousand, nine hundred one".