261493901 has 2 divisors, whose sum is σ = 261493902. Its totient is φ = 261493900.

The previous prime is 261493873. The next prime is 261493931. The reversal of 261493901 is 109394162.

261493901 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 255168676 + 6325225 = 15974^2 + 2515^2 .

It is a cyclic number.

It is not a de Polignac number, because 261493901 - 2¹⁸ = 261231757 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (261493931) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130746950 + 130746951.

It is an arithmetic number, because the mean of its divisors is an integer number (130746951).

Almost surely, 2^261493901 is an apocalyptic number.

It is an amenable number.

261493901 is a deficient number, since it is larger than the sum of its proper divisors (1).

261493901 is an equidigital number, since it uses as much as digits as its factorization.

261493901 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 11664, while the sum is 35.

The square root of 261493901 is about 16170.7730489300. The cubic root of 261493901 is about 639.4705101385.

The spelling of 261493901 in words is "two hundred sixty-one million, four hundred ninety-three thousand, nine hundred one".