1205665489 has 4 divisors (see below), whose sum is σ = 1377903424. Its totient is φ = 1033427556.

The previous prime is 1205665471. The next prime is 1205665493. The reversal of 1205665489 is 9845665021.

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 not a de Polignac number, because 1205665489 - 2⁵ = 1205665457 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1205665429) 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, 86118957 + ... + 86118970.

It is an arithmetic number, because the mean of its divisors is an integer number (344475856).

Almost surely, 2^1205665489 is an apocalyptic number.

It is an amenable number.

1205665489 is a deficient number, since it is larger than the sum of its proper divisors (172237935).

1205665489 is an equidigital number, since it uses as much as digits as its factorization.

1205665489 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 172237934.

The product of its (nonzero) digits is 518400, while the sum is 46.

The square root of 1205665489 is about 34722.6941495040. The cubic root of 1205665489 is about 1064.3282998757.

The spelling of 1205665489 in words is "one billion, two hundred five million, six hundred sixty-five thousand, four hundred eighty-nine".