261894497 has 4 divisors (see below), whose sum is σ = 262200240. Its totient is φ = 261588756.

The previous prime is 261894463. The next prime is 261894509. The reversal of 261894497 is 794498162.

261894497 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 261894497 - 2¹⁸ = 261632353 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261894407) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 151583 + ... + 153300.

It is an arithmetic number, because the mean of its divisors is an integer number (65550060).

Almost surely, 2^261894497 is an apocalyptic number.

It is an amenable number.

261894497 is a deficient number, since it is larger than the sum of its proper divisors (305743).

261894497 is an equidigital number, since it uses as much as digits as its factorization.

261894497 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 305742.

The product of its digits is 870912, while the sum is 50.

The square root of 261894497 is about 16183.1547295328. The cubic root of 261894497 is about 639.7968894864.

The spelling of 261894497 in words is "two hundred sixty-one million, eight hundred ninety-four thousand, four hundred ninety-seven".