77121515140 has 12 divisors (see below), whose sum is σ = 161955181836. Its totient is φ = 30848606048.

The previous prime is 77121515077. The next prime is 77121515143. The reversal of 77121515140 is 4151512177.

It can be written as a sum of positive squares in 2 ways, for example, as 41276423556 + 35845091584 = 203166^2 + 189328^2 .

It is a junction number, because it is equal to n+sod(n) for n = 77121515096 and 77121515105.

It is not an unprimeable number, because it can be changed into a prime (77121515143) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1928037859 + ... + 1928037898.

It is an arithmetic number, because the mean of its divisors is an integer number (13496265153).

Almost surely, 2^77121515140 is an apocalyptic number.

It is an amenable number.

77121515140 is an abundant number, since it is smaller than the sum of its proper divisors (84833666696).

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

77121515140 is a wasteful number, since it uses less digits than its factorization.

77121515140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3856075766 (or 3856075764 counting only the distinct ones).

The product of its (nonzero) digits is 9800, while the sum is 34.

The spelling of 77121515140 in words is "seventy-seven billion, one hundred twenty-one million, five hundred fifteen thousand, one hundred forty".