1209649 has 4 divisors (see below), whose sum is σ = 1382464. Its totient is φ = 1036836.

The previous prime is 1209647. The next prime is 1209671. The reversal of 1209649 is 9469021.

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, and also an emirpimes, since its reverse is a distinct semiprime: 9469021 = 2819 ⋅3359.

It is a cyclic number.

It is not a de Polignac number, because 1209649 - 2¹ = 1209647 is a prime.

It is a Duffinian number.

It is a plaindrome in base 13.

It is a self number, because there is not a number n which added to its sum of digits gives 1209649.

It is not an unprimeable number, because it can be changed into a prime (1209647) 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, 86397 + ... + 86410.

It is an arithmetic number, because the mean of its divisors is an integer number (345616).

2^1209649 is an apocalyptic number.

It is an amenable number.

1209649 is a deficient number, since it is larger than the sum of its proper divisors (172815).

1209649 is an equidigital number, since it uses as much as digits as its factorization.

1209649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 172814.

The product of its (nonzero) digits is 3888, while the sum is 31.

The square root of 1209649 is about 1099.8404429734. The cubic root of 1209649 is about 106.5499189230.

It can be divided in two parts, 12096 and 49, that multiplied together give a cube (592704 = 84³).

The spelling of 1209649 in words is "one million, two hundred nine thousand, six hundred forty-nine".