2661645 has 16 divisors (see below), whose sum is σ = 4867200. Its totient is φ = 1216704.

The previous prime is 2661643. The next prime is 2661647. The reversal of 2661645 is 5461662.

It is an interprime number because it is at equal distance from previous prime (2661643) and next prime (2661647).

It is not a de Polignac number, because 2661645 - 2¹ = 2661643 is a prime.

It is a super-3 number, since 3×2661645³ = 56568107053592733375, which contains 333 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2661641) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12570 + ... + 12779.

It is an arithmetic number, because the mean of its divisors is an integer number (304200).

2^2661645 is an apocalyptic number.

It is an amenable number.

2661645 is a deficient number, since it is larger than the sum of its proper divisors (2205555).

2661645 is a wasteful number, since it uses less digits than its factorization.

2661645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25364.

The product of its digits is 8640, while the sum is 30.

The square root of 2661645 is about 1631.4548721923. The cubic root of 2661645 is about 138.5851544436.

The spelling of 2661645 in words is "two million, six hundred sixty-one thousand, six hundred forty-five".