78723820 has 24 divisors (see below), whose sum is σ = 188937504. Its totient is φ = 26990976.

The previous prime is 78723817. The next prime is 78723829. The reversal of 78723820 is 2832787.

It is a self number, because there is not a number n which added to its sum of digits gives 78723820.

It is not an unprimeable number, because it can be changed into a prime (78723829) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 281017 + ... + 281296.

It is an arithmetic number, because the mean of its divisors is an integer number (7872396).

Almost surely, 2^78723820 is an apocalyptic number.

78723820 is a gapful number since it is divisible by the number (70) formed by its first and last digit.

It is an amenable number.

78723820 is an abundant number, since it is smaller than the sum of its proper divisors (110213684).

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

78723820 is a wasteful number, since it uses less digits than its factorization.

78723820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 562329 (or 562327 counting only the distinct ones).

The product of its (nonzero) digits is 37632, while the sum is 37.

The square root of 78723820 is about 8872.6444761413. The cubic root of 78723820 is about 428.5834401924.

The spelling of 78723820 in words is "seventy-eight million, seven hundred twenty-three thousand, eight hundred twenty".