2640406 has 8 divisors (see below), whose sum is σ = 4193640. Its totient is φ = 1242528.

The previous prime is 2640397. The next prime is 2640409. The reversal of 2640406 is 6040462.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2640409) 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, 38796 + ... + 38863.

It is an arithmetic number, because the mean of its divisors is an integer number (524205).

2^2640406 is an apocalyptic number.

2640406 is a deficient number, since it is larger than the sum of its proper divisors (1553234).

2640406 is a wasteful number, since it uses less digits than its factorization.

2640406 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 77678.

The product of its (nonzero) digits is 1152, while the sum is 22.

The square root of 2640406 is about 1624.9326139874. The cubic root of 2640406 is about 138.2155491659.

Adding to 2640406 its reverse (6040462), we get a palindrome (8680868).

The spelling of 2640406 in words is "two million, six hundred forty thousand, four hundred six".