65021577780 has 96 divisors (see below), whose sum is σ = 187056051840. Its totient is φ = 16863690240.

The previous prime is 65021577769. The next prime is 65021577787. The reversal of 65021577780 is 8777512056.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65021577787) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 7945731 + ... + 7953909.

It is an arithmetic number, because the mean of its divisors is an integer number (1948500540).

Almost surely, 2^65021577780 is an apocalyptic number.

65021577780 is a gapful number since it is divisible by the number (60) 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 65021577780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (93528025920).

65021577780 is an abundant number, since it is smaller than the sum of its proper divisors (122034474060).

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

65021577780 is a wasteful number, since it uses less digits than its factorization.

65021577780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11809 (or 11807 counting only the distinct ones).

The product of its (nonzero) digits is 823200, while the sum is 48.

The spelling of 65021577780 in words is "sixty-five billion, twenty-one million, five hundred seventy-seven thousand, seven hundred eighty".