2604781 has 4 divisors (see below), whose sum is σ = 2623932. Its totient is φ = 2585632.

The previous prime is 2604779. The next prime is 2604799. The reversal of 2604781 is 1874062.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1874062 = 2 ⋅937031.

It can be written as a sum of positive squares in 2 ways, for example, as 476100 + 2128681 = 690^2 + 1459^2 .

It is a cyclic number.

It is not a de Polignac number, because 2604781 - 2¹ = 2604779 is a prime.

It is a super-2 number, since 2×2604781² = 13569768115922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2604731) 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, 9370 + ... + 9643.

It is an arithmetic number, because the mean of its divisors is an integer number (655983).

2^2604781 is an apocalyptic number.

It is an amenable number.

2604781 is a deficient number, since it is larger than the sum of its proper divisors (19151).

2604781 is a wasteful number, since it uses less digits than its factorization.

2604781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19150.

The product of its (nonzero) digits is 2688, while the sum is 28.

The square root of 2604781 is about 1613.9333939169. The cubic root of 2604781 is about 137.5911197679.

It can be divided in two parts, 260 and 4781, that added together give a square (5041 = 71²).

The spelling of 2604781 in words is "two million, six hundred four thousand, seven hundred eighty-one".