77701220 has 48 divisors (see below), whose sum is σ = 173901168. Its totient is φ = 29061120.

The previous prime is 77701207. The next prime is 77701223. The reversal of 77701220 is 2210777.

It can be written as a sum of positive squares in 8 ways, for example, as 22733824 + 54967396 = 4768^2 + 7414^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 77701220.

It is not an unprimeable number, because it can be changed into a prime (77701223) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 58160 + ... + 59480.

It is an arithmetic number, because the mean of its divisors is an integer number (3622941).

Almost surely, 2^77701220 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 77701220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (86950584).

77701220 is an abundant number, since it is smaller than the sum of its proper divisors (96199948).

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

77701220 is a wasteful number, since it uses less digits than its factorization.

77701220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1520 (or 1518 counting only the distinct ones).

The product of its (nonzero) digits is 1372, while the sum is 26.

The square root of 77701220 is about 8814.8295502522. The cubic root of 77701220 is about 426.7196209774.

Adding to 77701220 its reverse (2210777), we get a palindrome (79911997).

The spelling of 77701220 in words is "seventy-seven million, seven hundred one thousand, two hundred twenty".