77820121514520 has 864 divisors, whose sum is σ = 329915769674400. Its totient is φ = 16170368670720.

The previous prime is 77820121514483. The next prime is 77820121514533. The reversal of 77820121514520 is 2541512102877.

77820121514520 is a `hidden beast` number, since 7 + 7 + 8 + 2 + 0 + 121 + 514 + 5 + 2 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

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 215 ways as a sum of consecutive naturals, for example, 222111636 + ... + 222461724.

Almost surely, 2^{77820121514520} is an apocalyptic number.

77820121514520 is a gapful number since it is divisible by the number (70) 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 77820121514520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (164957884837200).

77820121514520 is an abundant number, since it is smaller than the sum of its proper divisors (252095648159880).

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

77820121514520 is a wasteful number, since it uses less digits than its factorization.

77820121514520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 350153 (or 350117 counting only the distinct ones).

The product of its (nonzero) digits is 313600, while the sum is 45.

The spelling of 77820121514520 in words is "seventy-seven trillion, eight hundred twenty billion, one hundred twenty-one million, five hundred fourteen thousand, five hundred twenty".