777500020 has 72 divisors (see below), whose sum is σ = 1813014504. Its totient is φ = 279840000.

The previous prime is 777499963. The next prime is 777500021. The reversal of 777500020 is 20005777.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 96707556 + 680792464 = 9834^2 + 26092^2 .

It is a super-2 number, since 2×777500020² = 1209012562200000800, which contains 22 as substring.

It is a Smith number, since the sum of its digits (28) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (777500021) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 242830 + ... + 246010.

It is an arithmetic number, because the mean of its divisors is an integer number (25180757).

Almost surely, 2^777500020 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 777500020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (906507252).

777500020 is an abundant number, since it is smaller than the sum of its proper divisors (1035514484).

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

777500020 is a wasteful number, since it uses less digits than its factorization.

777500020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3313 (or 3300 counting only the distinct ones).

The product of its (nonzero) digits is 3430, while the sum is 28.

The square root of 777500020 is about 27883.6873458300. The cubic root of 777500020 is about 919.5319058574.

Adding to 777500020 its reverse (20005777), we get a palindrome (797505797).

The spelling of 777500020 in words is "seven hundred seventy-seven million, five hundred thousand, twenty".