7776981720 has 384 divisors, whose sum is σ = 28021593600. Its totient is φ = 1935166464.

The previous prime is 7776981679. The next prime is 7776981733. The reversal of 7776981720 is 271896777.

It is a super-3 number, since 3×7776981720³ (a number of 31 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 9612676 + ... + 9613484.

It is an arithmetic number, because the mean of its divisors is an integer number (72972900).

Almost surely, 2^7776981720 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 7776981720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (14010796800).

7776981720 is an abundant number, since it is smaller than the sum of its proper divisors (20244611880).

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

7776981720 is a wasteful number, since it uses less digits than its factorization.

7776981720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 901 (or 885 counting only the distinct ones).

The product of its (nonzero) digits is 2074464, while the sum is 54.

The square root of 7776981720 is about 88187.1970299544. The cubic root of 7776981720 is about 1981.2397194914.

The spelling of 7776981720 in words is "seven billion, seven hundred seventy-six million, nine hundred eighty-one thousand, seven hundred twenty".