77667820 has 48 divisors (see below), whose sum is σ = 172499040. Its totient is φ = 29293056.

The previous prime is 77667809. The next prime is 77667857. The reversal of 77667820 is 2876677.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 118614 + ... + 119266.

It is an arithmetic number, because the mean of its divisors is an integer number (3593730).

Almost surely, 2^77667820 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 77667820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (86249520).

77667820 is an abundant number, since it is smaller than the sum of its proper divisors (94831220).

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

77667820 is a wasteful number, since it uses less digits than its factorization.

77667820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 994 (or 992 counting only the distinct ones).

The product of its (nonzero) digits is 197568, while the sum is 43.

The square root of 77667820 is about 8812.9348119681. The cubic root of 77667820 is about 426.6584701659.

It can be divided in two parts, 77667 and 820, that added together give a palindrome (78487).

The spelling of 77667820 in words is "seventy-seven million, six hundred sixty-seven thousand, eight hundred twenty".