78401280 has 144 divisors (see below), whose sum is σ = 265343904. Its totient is φ = 19660800.

The previous prime is 78401269. The next prime is 78401293. The reversal of 78401280 is 8210487.

It is a super-2 number, since 2×78401280² = 12293521411276800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 64680 + ... + 65880.

It is an arithmetic number, because the mean of its divisors is an integer number (1842666).

Almost surely, 2^78401280 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 78401280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (132671952).

78401280 is an abundant number, since it is smaller than the sum of its proper divisors (186942624).

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

78401280 is a wasteful number, since it uses less digits than its factorization.

78401280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1242 (or 1228 counting only the distinct ones).

The product of its (nonzero) digits is 3584, while the sum is 30.

The square root of 78401280 is about 8854.4497288087. The cubic root of 78401280 is about 427.9973214378.

The spelling of 78401280 in words is "seventy-eight million, four hundred one thousand, two hundred eighty".