7640856215 has 4 divisors (see below), whose sum is σ = 9169027464. Its totient is φ = 6112684968.

The previous prime is 7640856211. The next prime is 7640856241. The reversal of 7640856215 is 5126580467.

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

It is a cyclic number.

It is not a de Polignac number, because 7640856215 - 2² = 7640856211 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7640856211) 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, 764085617 + ... + 764085626.

It is an arithmetic number, because the mean of its divisors is an integer number (2292256866).

Almost surely, 2^7640856215 is an apocalyptic number.

7640856215 is a deficient number, since it is larger than the sum of its proper divisors (1528171249).

7640856215 is a wasteful number, since it uses less digits than its factorization.

7640856215 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1528171248.

The product of its (nonzero) digits is 403200, while the sum is 44.

The square root of 7640856215 is about 87411.9912540608. The cubic root of 7640856215 is about 1969.6119736163.

The spelling of 7640856215 in words is "seven billion, six hundred forty million, eight hundred fifty-six thousand, two hundred fifteen".