78219217440 has 864 divisors, whose sum is σ = 336688999920. Its totient is φ = 16390176768.

The previous prime is 78219217403. The next prime is 78219217477. The reversal of 78219217440 is 4471291287.

78219217440 is a `hidden beast` number, since 7 + 8 + 2 + 192 + 17 + 440 = 666.

It is an interprime number because it is at equal distance from previous prime (78219217403) and next prime (78219217477).

It can be written as a sum of positive squares in 8 ways, for example, as 22924944 + 78196292496 = 4788^2 + 279636^2 .

It is a super-2 number, since 2×78219217440² (a number of 23 digits) contains 22 as substring.

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

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 246748162 + ... + 246748478.

Almost surely, 2^78219217440 is an apocalyptic number.

78219217440 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 78219217440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (168344499960).

78219217440 is an abundant number, since it is smaller than the sum of its proper divisors (258469782480).

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

78219217440 is a wasteful number, since it uses less digits than its factorization.

78219217440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 634 (or 616 counting only the distinct ones).

The product of its (nonzero) digits is 225792, while the sum is 45.

The spelling of 78219217440 in words is "seventy-eight billion, two hundred nineteen million, two hundred seventeen thousand, four hundred forty".