65309778612 has 144 divisors (see below), whose sum is σ = 184294190080. Its totient is φ = 19365350400.

The previous prime is 65309778601. The next prime is 65309778631. The reversal of 65309778612 is 21687790356.

65309778612 is a `hidden beast` number, since 6 + 530 + 97 + 7 + 8 + 6 + 12 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 3487089 + ... + 3505767.

Almost surely, 2^65309778612 is an apocalyptic number.

65309778612 is a gapful number since it is divisible by the number (62) 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 65309778612, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (92147095040).

65309778612 is an abundant number, since it is smaller than the sum of its proper divisors (118984411468).

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

65309778612 is a wasteful number, since it uses less digits than its factorization.

65309778612 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18974 (or 18969 counting only the distinct ones).

The product of its (nonzero) digits is 3810240, while the sum is 54.

The spelling of 65309778612 in words is "sixty-five billion, three hundred nine million, seven hundred seventy-eight thousand, six hundred twelve".