7777969920 has 540 divisors, whose sum is σ = 32395981464. Its totient is φ = 1776660480.

The previous prime is 7777969919. The next prime is 7777969921. The reversal of 7777969920 is 299697777.

It is an interprime number because it is at equal distance from previous prime (7777969919) and next prime (7777969921).

It is a tau number, because it is divible by the number of its divisors (540).

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7777969921) by changing a digit.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 5079555 + ... + 5081085.

Almost surely, 2^7777969920 is an apocalyptic number.

7777969920 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 7777969920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (16197990732).

7777969920 is an abundant number, since it is smaller than the sum of its proper divisors (24618011544).

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

7777969920 is a wasteful number, since it uses less digits than its factorization.

7777969920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1578 (or 1548 counting only the distinct ones).

The product of its (nonzero) digits is 21003948, while the sum is 63.

The square root of 7777969920 is about 88192.7997060985. The cubic root of 7777969920 is about 1981.3236328587.

The spelling of 7777969920 in words is "seven billion, seven hundred seventy-seven million, nine hundred sixty-nine thousand, nine hundred twenty".