261090889 has 4 divisors (see below), whose sum is σ = 263625856. Its totient is φ = 258555924.

The previous prime is 261090887. The next prime is 261090899. The reversal of 261090889 is 988090162.

It is a happy number.

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 261090889 - 2¹ = 261090887 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261090881) 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, 1267329 + ... + 1267534.

It is an arithmetic number, because the mean of its divisors is an integer number (65906464).

Almost surely, 2^261090889 is an apocalyptic number.

It is an amenable number.

261090889 is a deficient number, since it is larger than the sum of its proper divisors (2534967).

261090889 is a wasteful number, since it uses less digits than its factorization.

261090889 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2534966.

The product of its (nonzero) digits is 62208, while the sum is 43.

The square root of 261090889 is about 16158.3071204876. The cubic root of 261090889 is about 639.1418258654.

The spelling of 261090889 in words is "two hundred sixty-one million, ninety thousand, eight hundred eighty-nine".