261122791 has 2 divisors, whose sum is σ = 261122792. Its totient is φ = 261122790.

The previous prime is 261122747. The next prime is 261122803. The reversal of 261122791 is 197221162.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 261122791 - 2¹⁷ = 260991719 is a prime.

It is a super-2 number, since 2×261122791² = 136370223959259362, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (261122711) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130561395 + 130561396.

It is an arithmetic number, because the mean of its divisors is an integer number (130561396).

Almost surely, 2^261122791 is an apocalyptic number.

261122791 is a deficient number, since it is larger than the sum of its proper divisors (1).

261122791 is an equidigital number, since it uses as much as digits as its factorization.

261122791 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3024, while the sum is 31.

The square root of 261122791 is about 16159.2942605796. The cubic root of 261122791 is about 639.1678564840.

The spelling of 261122791 in words is "two hundred sixty-one million, one hundred twenty-two thousand, seven hundred ninety-one".