64781381912 has 32 divisors (see below), whose sum is σ = 131020696800. Its totient is φ = 29850610944.

The previous prime is 64781381911. The next prime is 64781381941. The reversal of 64781381912 is 21918318746.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64781381911) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 440612 + ... + 568947.

It is an arithmetic number, because the mean of its divisors is an integer number (4094396775).

Almost surely, 2^64781381912 is an apocalyptic number.

It is an amenable number.

64781381912 is an abundant number, since it is smaller than the sum of its proper divisors (66239314888).

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

64781381912 is a wasteful number, since it uses less digits than its factorization.

64781381912 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1010195 (or 1010191 counting only the distinct ones).

The product of its digits is 580608, while the sum is 50.

The spelling of 64781381912 in words is "sixty-four billion, seven hundred eighty-one million, three hundred eighty-one thousand, nine hundred twelve".