2638665 has 24 divisors (see below), whose sum is σ = 4612608. Its totient is φ = 1395360.

The previous prime is 2638651. The next prime is 2638667. The reversal of 2638665 is 5668362.

It is not a de Polignac number, because 2638665 - 2⁵ = 2638633 is a prime.

It is a Curzon number.

2638665 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (2638667) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 8442 + ... + 8748.

It is an arithmetic number, because the mean of its divisors is an integer number (192192).

2^2638665 is an apocalyptic number.

It is an amenable number.

2638665 is a deficient number, since it is larger than the sum of its proper divisors (1973943).

2638665 is a wasteful number, since it uses less digits than its factorization.

2638665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 509 (or 506 counting only the distinct ones).

The product of its digits is 51840, while the sum is 36.

The square root of 2638665 is about 1624.3968111271. The cubic root of 2638665 is about 138.1851641697.

The spelling of 2638665 in words is "two million, six hundred thirty-eight thousand, six hundred sixty-five".