261161851 has 2 divisors, whose sum is σ = 261161852. Its totient is φ = 261161850.

The previous prime is 261161843. The next prime is 261161881. The reversal of 261161851 is 158161162.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 261161851 - 2³ = 261161843 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (261161881) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130580925 + 130580926.

It is an arithmetic number, because the mean of its divisors is an integer number (130580926).

Almost surely, 2^261161851 is an apocalyptic number.

261161851 is a deficient number, since it is larger than the sum of its proper divisors (1).

261161851 is an equidigital number, since it uses as much as digits as its factorization.

261161851 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2880, while the sum is 31.

The square root of 261161851 is about 16160.5028077718. The cubic root of 261161851 is about 639.1997248267.

The spelling of 261161851 in words is "two hundred sixty-one million, one hundred sixty-one thousand, eight hundred fifty-one".