78289240 has 64 divisors (see below), whose sum is σ = 188179200. Its totient is φ = 29242752.

The previous prime is 78289223. The next prime is 78289243. The reversal of 78289240 is 4298287.

It is a super-2 number, since 2×78289240² = 12258410199555200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a junction number, because it is equal to n+sod(n) for n = 78289193 and 78289202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78289243) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 38571 + ... + 40549.

It is an arithmetic number, because the mean of its divisors is an integer number (2940300).

Almost surely, 2^78289240 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 78289240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (94089600).

78289240 is an abundant number, since it is smaller than the sum of its proper divisors (109889960).

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

78289240 is a wasteful number, since it uses less digits than its factorization.

78289240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2056 (or 2052 counting only the distinct ones).

The product of its (nonzero) digits is 64512, while the sum is 40.

The square root of 78289240 is about 8848.1207044208. The cubic root of 78289240 is about 427.7933465346.

78289240 divided by its sum of digits (40) gives a triangular number (1957231 = T₁₉₇₈).

The spelling of 78289240 in words is "seventy-eight million, two hundred eighty-nine thousand, two hundred forty".