7851640625 has 16 divisors (see below), whose sum is σ = 9814623312. Its totient is φ = 6281250000.

The previous prime is 7851640619. The next prime is 7851640631. The reversal of 7851640625 is 5260461587.

It is an interprime number because it is at equal distance from previous prime (7851640619) and next prime (7851640631).

It can be written as a sum of positive squares in 8 ways, for example, as 4709253376 + 3142387249 = 68624^2 + 56057^2 .

It is not a de Polignac number, because 7851640625 - 2¹⁶ = 7851575089 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 27875 + ... + 128375.

It is an arithmetic number, because the mean of its divisors is an integer number (613413957).

Almost surely, 2^7851640625 is an apocalyptic number.

It is an amenable number.

7851640625 is a deficient number, since it is larger than the sum of its proper divisors (1962982687).

7851640625 is an frugal number, since it uses more digits than its factorization.

7851640625 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 100536 (or 100506 counting only the distinct ones).

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

The square root of 7851640625 is about 88609.4838321497. The cubic root of 7851640625 is about 1987.5594961291.

The spelling of 7851640625 in words is "seven billion, eight hundred fifty-one million, six hundred forty thousand, six hundred twenty-five".