261916693 has 2 divisors, whose sum is σ = 261916694. Its totient is φ = 261916692.

The previous prime is 261916687. The next prime is 261916717. The reversal of 261916693 is 396619162.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 226893969 + 35022724 = 15063^2 + 5918^2 .

It is a cyclic number.

It is not a de Polignac number, because 261916693 - 2¹⁷ = 261785621 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (261916643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130958346 + 130958347.

It is an arithmetic number, because the mean of its divisors is an integer number (130958347).

Almost surely, 2^261916693 is an apocalyptic number.

It is an amenable number.

261916693 is a deficient number, since it is larger than the sum of its proper divisors (1).

261916693 is an equidigital number, since it uses as much as digits as its factorization.

261916693 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 104976, while the sum is 43.

The square root of 261916693 is about 16183.8404898219. The cubic root of 261916693 is about 639.8149635974.

The spelling of 261916693 in words is "two hundred sixty-one million, nine hundred sixteen thousand, six hundred ninety-three".