78401209320 has 288 divisors, whose sum is σ = 298303036200. Its totient is φ = 17805505536.

The previous prime is 78401209319. The next prime is 78401209321. The reversal of 78401209320 is 2390210487.

It is an interprime number because it is at equal distance from previous prime (78401209319) and next prime (78401209321).

It can be written as a sum of positive squares in 4 ways, for example, as 52915641156 + 25485568164 = 230034^2 + 159642^2 .

It is a super-2 number, since 2×78401209320² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (78401209321) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 2755326 + ... + 2783634.

Almost surely, 2^78401209320 is an apocalyptic number.

78401209320 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 78401209320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (149151518100).

78401209320 is an abundant number, since it is smaller than the sum of its proper divisors (219901826880).

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

78401209320 is a wasteful number, since it uses less digits than its factorization.

78401209320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28497 (or 28483 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 36.

The spelling of 78401209320 in words is "seventy-eight billion, four hundred one million, two hundred nine thousand, three hundred twenty".