7838812665 has 40 divisors (see below), whose sum is σ = 14536364040. Its totient is φ = 4036531968.

The previous prime is 7838812661. The next prime is 7838812687. The reversal of 7838812665 is 5662188387.

It can be written as a sum of positive squares in 4 ways, for example, as 649638144 + 7189174521 = 25488^2 + 84789^2 .

It is not a de Polignac number, because 7838812665 - 2² = 7838812661 is a prime.

It is a super-2 number, since 2×7838812665² (a number of 21 digits) contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (7838812661) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 321964 + ... + 345453.

It is an arithmetic number, because the mean of its divisors is an integer number (363409101).

Almost surely, 2^7838812665 is an apocalyptic number.

It is an amenable number.

7838812665 is a deficient number, since it is larger than the sum of its proper divisors (6697551375).

7838812665 is a wasteful number, since it uses less digits than its factorization.

7838812665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 667463 (or 667454 counting only the distinct ones).

The product of its digits is 3870720, while the sum is 54.

The square root of 7838812665 is about 88537.0694398680. The cubic root of 7838812665 is about 1986.4764854651.

The spelling of 7838812665 in words is "seven billion, eight hundred thirty-eight million, eight hundred twelve thousand, six hundred sixty-five".