7640405 has 8 divisors (see below), whose sum is σ = 9227832. Its totient is φ = 6072768.

The previous prime is 7640377. The next prime is 7640411. The reversal of 7640405 is 5040467.

It can be written as a sum of positive squares in 4 ways, for example, as 1295044 + 6345361 = 1138^2 + 2519^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 7640405 - 2⁶ = 7640341 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4082 + ... + 5651.

It is an arithmetic number, because the mean of its divisors is an integer number (1153479).

Almost surely, 2^7640405 is an apocalyptic number.

It is an amenable number.

7640405 is a deficient number, since it is larger than the sum of its proper divisors (1587427).

7640405 is a wasteful number, since it uses less digits than its factorization.

7640405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9895.

The product of its (nonzero) digits is 3360, while the sum is 26.

The square root of 7640405 is about 2764.1282531749. The cubic root of 7640405 is about 196.9573202396.

The spelling of 7640405 in words is "seven million, six hundred forty thousand, four hundred five".