78244308691640 has 384 divisors, whose sum is σ = 226575474531840. Its totient is φ = 24086423015424.

The previous prime is 78244308691579. The next prime is 78244308691651. The reversal of 78244308691640 is 4619680344287.

It is a happy number.

It is a super-2 number, since 2×78244308691640² (a number of 29 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 3655069817 + ... + 3655091223.

It is an arithmetic number, because the mean of its divisors is an integer number (590040298260).

Almost surely, 2^{78244308691640} is an apocalyptic number.

78244308691640 is a gapful number since it is divisible by the number (70) 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 78244308691640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (113287737265920).

78244308691640 is an abundant number, since it is smaller than the sum of its proper divisors (148331165840200).

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

78244308691640 is a wasteful number, since it uses less digits than its factorization.

78244308691640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25359 (or 25348 counting only the distinct ones).

The product of its (nonzero) digits is 55738368, while the sum is 62.

The spelling of 78244308691640 in words is "seventy-eight trillion, two hundred forty-four billion, three hundred eight million, six hundred ninety-one thousand, six hundred forty".