7738539978 has 64 divisors (see below), whose sum is σ = 18058626432. Its totient is φ = 2188892160.

The previous prime is 7738539953. The next prime is 7738539997. The reversal of 7738539978 is 8799358377.

It is a super-2 number, since 2×7738539978² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 10843 + ... + 124878.

It is an arithmetic number, because the mean of its divisors is an integer number (282166038).

Almost surely, 2^7738539978 is an apocalyptic number.

7738539978 is a gapful number since it is divisible by the number (78) formed by its first and last digit.

7738539978 is an abundant number, since it is smaller than the sum of its proper divisors (10320086454).

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

7738539978 is a wasteful number, since it uses less digits than its factorization.

7738539978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 135799.

The product of its digits is 80015040, while the sum is 66.

The square root of 7738539978 is about 87968.9716775182. The cubic root of 7738539978 is about 1977.9698930076.

The spelling of 7738539978 in words is "seven billion, seven hundred thirty-eight million, five hundred thirty-nine thousand, nine hundred seventy-eight".