64861363440 has 640 divisors, whose sum is σ = 251083929600. Its totient is φ = 15303720960.

The previous prime is 64861363439. The next prime is 64861363447. The reversal of 64861363440 is 4436316846.

It is a happy number.

64861363440 is a `hidden beast` number, since 6 + 4 + 8 + 6 + 1 + 3 + 634 + 4 + 0 = 666.

64861363440 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64861363447) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 51517531 + ... + 51518789.

It is an arithmetic number, because the mean of its divisors is an integer number (392318640).

Almost surely, 2^64861363440 is an apocalyptic number.

64861363440 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 64861363440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (125541964800).

64861363440 is an abundant number, since it is smaller than the sum of its proper divisors (186222566160).

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

64861363440 is a wasteful number, since it uses less digits than its factorization.

64861363440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1382 (or 1370 counting only the distinct ones).

The product of its (nonzero) digits is 995328, while the sum is 45.

The spelling of 64861363440 in words is "sixty-four billion, eight hundred sixty-one million, three hundred sixty-three thousand, four hundred forty".