7640657 has 4 divisors (see below), whose sum is σ = 7662900. Its totient is φ = 7618416.

The previous prime is 7640621. The next prime is 7640681. The reversal of 7640657 is 7560467.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 7560467 = 47 ⋅160861.

It can be written as a sum of positive squares in 2 ways, for example, as 5683456 + 1957201 = 2384^2 + 1399^2 .

It is a cyclic number.

It is not a de Polignac number, because 7640657 - 2¹⁰ = 7639633 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (7640617) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10598 + ... + 11295.

It is an arithmetic number, because the mean of its divisors is an integer number (1915725).

Almost surely, 2^7640657 is an apocalyptic number.

It is an amenable number.

7640657 is a deficient number, since it is larger than the sum of its proper divisors (22243).

7640657 is a wasteful number, since it uses less digits than its factorization.

7640657 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22242.

The product of its (nonzero) digits is 35280, while the sum is 35.

The square root of 7640657 is about 2764.1738367910. The cubic root of 7640657 is about 196.9594856003.

The spelling of 7640657 in words is "seven million, six hundred forty thousand, six hundred fifty-seven".