78263640 has 192 divisors, whose sum is σ = 313185600. Its totient is φ = 16505856.

The previous prime is 78263639. The next prime is 78263651. The reversal of 78263640 is 4636287.

78263640 is a `hidden beast` number, since 7 + 8 + 2 + 6 + 3 + 640 = 666.

It is a super-2 number, since 2×78263640² = 12250394692099200, which contains 22 as substring.

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

It is a junction number, because it is equal to n+sod(n) for n = 78263595 and 78263604.

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, 31566 + ... + 33954.

It is an arithmetic number, because the mean of its divisors is an integer number (1631175).

Almost surely, 2^78263640 is an apocalyptic number.

78263640 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 78263640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (156592800).

78263640 is an abundant number, since it is smaller than the sum of its proper divisors (234921960).

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

78263640 is a wasteful number, since it uses less digits than its factorization.

78263640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2426 (or 2419 counting only the distinct ones).

The product of its (nonzero) digits is 48384, while the sum is 36.

The square root of 78263640 is about 8846.6739512655. The cubic root of 78263640 is about 427.7467130356.

The spelling of 78263640 in words is "seventy-eight million, two hundred sixty-three thousand, six hundred forty".