2640686 has 4 divisors (see below), whose sum is σ = 3961032. Its totient is φ = 1320342.

The previous prime is 2640683. The next prime is 2640689. The reversal of 2640686 is 6860462.

It is a happy number.

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

It is an interprime number because it is at equal distance from previous prime (2640683) and next prime (2640689).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2640683) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 660170 + ... + 660173.

It is an arithmetic number, because the mean of its divisors is an integer number (990258).

2^2640686 is an apocalyptic number.

2640686 is a deficient number, since it is larger than the sum of its proper divisors (1320346).

2640686 is a wasteful number, since it uses less digits than its factorization.

2640686 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1320345.

The product of its (nonzero) digits is 13824, while the sum is 32.

The square root of 2640686 is about 1625.0187691224. The cubic root of 2640686 is about 138.2204346502.

The spelling of 2640686 in words is "two million, six hundred forty thousand, six hundred eighty-six".