78645840 has 240 divisors, whose sum is σ = 302802048. Its totient is φ = 16533504.

The previous prime is 78645823. The next prime is 78645851. The reversal of 78645840 is 4854687.

It is a tau number, because it is divible by the number of its divisors (240).

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a junction number, because it is equal to n+sod(n) for n = 78645792 and 78645801.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 283782 + ... + 284058.

Almost surely, 2^78645840 is an apocalyptic number.

78645840 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 78645840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (151401024).

78645840 is an abundant number, since it is smaller than the sum of its proper divisors (224156208).

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

78645840 is a wasteful number, since it uses less digits than its factorization.

78645840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 326 (or 307 counting only the distinct ones).

The product of its (nonzero) digits is 215040, while the sum is 42.

The square root of 78645840 is about 8868.2489816198. The cubic root of 78645840 is about 428.4418821151.

The spelling of 78645840 in words is "seventy-eight million, six hundred forty-five thousand, eight hundred forty".