78209280 has 288 divisors, whose sum is σ = 290411520. Its totient is φ = 19906560.

The previous prime is 78209251. The next prime is 78209293. The reversal of 78209280 is 8290287.

It is a tau number, because it is divible by the number of its divisors (288).

It is a super-2 number, since 2×78209280² = 12233382956236800, which contains 22 as substring.

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

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1071324 + ... + 1071396.

Almost surely, 2^78209280 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 78209280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (145205760).

78209280 is an abundant number, since it is smaller than the sum of its proper divisors (212202240).

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

78209280 is a wasteful number, since it uses less digits than its factorization.

78209280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 134 (or 114 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 36.

The square root of 78209280 is about 8843.6010764846. The cubic root of 78209280 is about 427.6476559814.

The spelling of 78209280 in words is "seventy-eight million, two hundred nine thousand, two hundred eighty".