7664486778 has 48 divisors (see below), whose sum is σ = 18135726336. Its totient is φ = 2325083040.

The previous prime is 7664486777. The next prime is 7664486801. The reversal of 7664486778 is 8776844667.

7664486778 is a `hidden beast` number, since 7 + 66 + 448 + 67 + 78 = 666.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (7664486777) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 214050 + ... + 247277.

It is an arithmetic number, because the mean of its divisors is an integer number (377827632).

Almost surely, 2^7664486778 is an apocalyptic number.

7664486778 is a gapful number since it is divisible by the number (78) formed by its first and last digit.

7664486778 is an abundant number, since it is smaller than the sum of its proper divisors (10471239558).

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

7664486778 is a wasteful number, since it uses less digits than its factorization.

7664486778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 461419 (or 461416 counting only the distinct ones).

The product of its digits is 75866112, while the sum is 63.

The square root of 7664486778 is about 87547.0546506277. The cubic root of 7664486778 is about 1971.6403301339.

The spelling of 7664486778 in words is "seven billion, six hundred sixty-four million, four hundred eighty-six thousand, seven hundred seventy-eight".