2978609 has 4 divisors (see below), whose sum is σ = 3051300. Its totient is φ = 2905920.

The previous prime is 2978593. The next prime is 2978627. The reversal of 2978609 is 9068792.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 418609 + 2560000 = 647^2 + 1600^2 .

It is a cyclic number.

It is not a de Polignac number, because 2978609 - 2⁴ = 2978593 is a prime.

It is a super-2 number, since 2×2978609² = 17744223149762, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (41), and also a Moran number because the ratio is a prime number: 72649 = 2978609 / (2 + 9 + 7 + 8 + 6 + 0 + 9).

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (2978629) 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, 36284 + ... + 36365.

It is an arithmetic number, because the mean of its divisors is an integer number (762825).

2^2978609 is an apocalyptic number.

It is an amenable number.

2978609 is a deficient number, since it is larger than the sum of its proper divisors (72691).

2978609 is an equidigital number, since it uses as much as digits as its factorization.

2978609 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72690.

The product of its (nonzero) digits is 54432, while the sum is 41.

The square root of 2978609 is about 1725.8647108044. The cubic root of 2978609 is about 143.8813483778.

The spelling of 2978609 in words is "two million, nine hundred seventy-eight thousand, six hundred nine".