7640165988 has 144 divisors (see below), whose sum is σ = 23848546176. Its totient is φ = 2008281600.

The previous prime is 7640165987. The next prime is 7640165989. The reversal of 7640165988 is 8895610467.

7640165988 is a `hidden beast` number, since 7 + 6 + 40 + 1 + 6 + 598 + 8 = 666.

It is an interprime number because it is at equal distance from previous prime (7640165987) and next prime (7640165989).

It is a super-2 number, since 2×7640165988² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (7640165987) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1021663 + ... + 1029113.

It is an arithmetic number, because the mean of its divisors is an integer number (165614904).

Almost surely, 2^7640165988 is an apocalyptic number.

7640165988 is a gapful number since it is divisible by the number (78) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 7640165988, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (11924273088).

7640165988 is an abundant number, since it is smaller than the sum of its proper divisors (16208380188).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

7640165988 is a wasteful number, since it uses less digits than its factorization.

7640165988 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7794 (or 7789 counting only the distinct ones).

The product of its (nonzero) digits is 2903040, while the sum is 54.

The square root of 7640165988 is about 87408.0430395281. The cubic root of 7640165988 is about 1969.5526643686.

The spelling of 7640165988 in words is "seven billion, six hundred forty million, one hundred sixty-five thousand, nine hundred eighty-eight".