261998411 has 2 divisors, whose sum is σ = 261998412. Its totient is φ = 261998410.

The previous prime is 261998311. The next prime is 261998413. The reversal of 261998411 is 114899162.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-261998411 is a prime.

Together with 261998413, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (261998413) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130999205 + 130999206.

It is an arithmetic number, because the mean of its divisors is an integer number (130999206).

Almost surely, 2^261998411 is an apocalyptic number.

261998411 is a deficient number, since it is larger than the sum of its proper divisors (1).

261998411 is an equidigital number, since it uses as much as digits as its factorization.

261998411 is an evil number, because the sum of its binary digits is even.

The product of its digits is 31104, while the sum is 41.

The square root of 261998411 is about 16186.3649717903. The cubic root of 261998411 is about 639.8814974279.

The spelling of 261998411 in words is "two hundred sixty-one million, nine hundred ninety-eight thousand, four hundred eleven".